Chris Perry, Author

Category: Japanese History

Kings in the North, Part 3

Last time, we looked at how Date Masamune defied an order from Toyotomi Hideyoshi to end his local wars. In 1590, the Date were summoned to take part in the upcoming campaign against the Hojo, based at Odawara, and Masamune knew better than to push his luck. Hideyoshi, however, had not forgotten his earlier defiance.

Date Masamune

When Masamune arrived at Odawara, he was stripped of all the territory he had taken in Aizu and confined to the 13 counties in Mutsu and Dewa Provinces that the Date had controlled before the peace order, obliging Masamune to leave the recently conquered Kurokawa Castle and return to his family’s seat at Yonezawa. In 1591, a rebellion broke out in Masamune’s home province, and after he put it down, letters were ‘found’ that implicated Masamune in instigating the violence.

The rumours reached Hideyoshi in Kyoto, and he ordered Masamune to come in person to explain himself, which he promptly did, eventually being pardoned, but having his territory reduced still further. Despite the fact that Masamune then fought in Hideyoshi’s invasion of Korea, it wasn’t long before further rumours of treason surrounded him.

In 1595, Hideyoshi’s nephew, Hidetsugu, was accused of treason, allegedly plotting either to overthrow his uncle or else usurp the regency after his death. Even at the time, the accusations were considered dubious, and the exact reasons are still murky today, but Hidetsugu was obliged to commit seppuku, and 39 members of his family and household were purged (read, murdered).

Toyotomi Hidetsugu. The accusations of his treasonous conduct were considered dubious even at the time.

The brutality of the crackdown and the somewhat flimsy evidence would eventually backfire for Hideyoshi, but for now, we can focus on how this purge would eventually involve Masamune. He and Hidetsugu had enjoyed a close relationship, and when accusations of treason were being thrown around, it didn’t take long for people to point that out.

Masamune was summoned to explain himself once again. He had good reason to worry; his cousin had been Hidetsugu’s concubine (and had died in the purge), and it was widely thought that Hideyoshi believed that Masamune was guilty. In the end, a combination of Masamune’s eloquent denial and the intervention of several influential retainers led to his pardon. He was, however, obliged to sign a document, witnessed (and potentially enforced) by 19 powerful vassals, stating that if he were ever to commit treason, his position as head of his clan would be forfeit.

Hideyoshi died in 1598, leaving his young son in the care of a council of five regents. Masamune was not on this council, but he quickly reached an understanding with Tokugawa Ieyasu, arguably the council’s most powerful member. In 1599, Masamune’s daughter married Ieyasu’s fifth son, something that was believed to be an example of Ieyasu securing illegal alliances, though modern scholars suggest that this is an example of a violation of the ‘spirit’ rather than the letter of the law.

Tokugawa Ieyasu. He found a willing ally in Masamune.

By 1600, it had become clear that the Council of Regents was not going to last, and a new conflict swiftly broke out. Ieyasu secured the support of Masamune by promising to restore all the lands he had lost in 1590. Date forces would not be present at the decisive Battle of Sekigahara, however, and despite some successes against Ieyasu’s enemies in the north, an attempt to retake the promised territories by force was ultimately unsuccessful.

Despite this, Masamune still petitioned Ieyasu for the return of the territory, which Ieyasu refused to do, and in fact, Date lands were reduced further (though they would remain the fifth richest clan by koku (rice production)). In 1601, Masamune moved his headquarters to Sendai, establishing the Sendai Domain, which would continue to be the centre of the Date Clan for the next 250 years.

Though distant from the capital and never entirely trusted, Masamune would play a significant role in Japan’s future. In 1613, he ordered the construction of a European-style galleon, the San Juan Bautista. Masamune was the only Daimyo to receive permission from the Tokugawa to send missions overseas to represent Japan. The so-called Keicho Embassy departed Japan in October 1613, travelling across the Pacific to New Spain (modern Mexico) and from there, across the Atlantic to Europe. The embassy would receive an audience with the King of Spain in January 1615, and then one with the Pope in October of the same year. The Embassy would not return to Japan until 1620, by which time Christianity had been outlawed by the Shogunate, meaning that the Ambassador and anyone involved had come under suspicion.

A European portrait of Hasekura Tsunenaga, the ambassador in the Keicho Embassy. By the time he returned to Japan, Christianity had been outlawed, and his achievement as the first Japanese representative to Europe was largely forgotten.

Meanwhile, Masamune at the Date had continued to support the new Shogunate, taking part in both Sieges of Osaka in 1614-15. However, once again, Masamune would find himself under attack by rumours of treason, this time after a supposed ‘friendly fire’ incident, in which Date troops fired on their allies. It’s not clear from surviving records if this incident actually happened, but in 1616, the rumour spread that Ieyasu planned to march against the Date.

When the two men met in early 1616, Masamune was cleared of any suspicion, and after Ieyasu passed away in June of that year, any serious suggestion that the Date and Tokugawa would go to war seems to have died out (though later texts suggest that Masamune had a plan to fight the Shogunate, should it come down to it)

With the age of constant civil war coming to an end, Masamune focused on developing his home territory. He ordered the construction of a canal that became the Teizan Canal (though it wouldn’t take its final form until the 19th century). He established a port at Ishinomaki, which was heavily damaged in a tsunami in 2011, and has since been largely rebuilt.

The Teizan Canal as it appears today. Though largely remodelled in the 19th century, its origins lay with Masamune in the 1600s.

He also developed agriculture in the Kitakami River basin, which remains a major rice producer to this day. In the Edo Period, the Sendai Domain was valued at around 620,000 koku, but produced in excess of 745,000 koku annually, indicating how effective Masamune’s investments had been, and how inefficient Japanese land valuation was in the pre-modern period.

In his later years, Masamune would establish a warmer relationship with the Shogunate than he had known previously. When the third Shogun, Iemitsu, began to rule in his own right in 1632, he was said to have idolised Masamune, who by then was one of the last remaining Daimyo to have actually fought during the Sengoku period. The Shogun is said to have frequently asked Masamune for stories of the period, especially the battles he had fought, and what it had been like to serve Ieyasu and Hideyoshi (both of whom were legendary figures by that point)

Masamune remained vigorous until late in life, but in 1634, he began to develop serious health problems, and his condition declined quickly before he eventually passed away in June 1636. His death was mourned in Edo, with the Shogun banning revelry, fishing, and even the playing of music for seven days afterwards.

Zuihoden, in modern Sendai, the final resting place of Date Masamune.
_{^{663highland 投稿者自身による著作物, CC 表示 2.5, https://commons.wikimedia.org/w/index.php?curid=2631054による}}

Masamune’s reforms and investments had left the Date in a strong financial position, and the Clan would often be treated generally by the Shogunate, with the clan being one of the few ‘outside’ Daimyo (a clan that had not been a vassal of the Tokugawa before Sekigahara) who was granted a marriage into the Shogun’s family.

Despite, or perhaps because of this, the third Lord, Tsunamune (Masamune’s grandson), proved to be something of a “rich kid” spending his days engaged in what is politely called “debauchery”. Although a certain amount of wine, women (or men), and song was expected of a Daimyo, Tsunamune was extreme to the point that his retainers tried to get rid of him. In August 1660, they petitioned the Shogunate directly, asking that Tsunamune be removed.

The Shogunate agreed, replacing Tsunamune with his two-year-old son, Tsunamura. Given his young age, Tsunamura needed a regent, and what followed was a decade of violence as rival factions sought influence over the young Lord. Finally, in 1671, a meeting was called in the house of Sakai Tadakiyo, a roju (senior minister) in Edo.

Date Tsunamune, whose debauchery led to his downfall, and nearly that of his clan.

What was supposed to be a peaceful meeting to seek a solution to the ongoing violence in Sendai quickly turned into a bloody brawl, and by the end of it, swords had been drawn, and several men lay dead. Tsunamune, as a child, was not held responsible, but the families of those responsible for the bloodshed were executed in turn (in line with the law at the time).

As the Edo Period went on, the Sendai Domain, much like many Samurai holdings, began to suffer economic hardship. The problem was that the value of the land was estimated based on rice production in the 17th century, and by the early 19th century, those numbers simply didn’t add up.

Financial problems didn’t stop the Date from remaining loyal to the Tokugawa; during the Boshin War in 1868-69, the Sendai Domain was central to the Shogunate’s efforts to retain power. The Shogunate would ultimately lose the war, and the Date had their lands confiscated, though they were partially restored in the peace that followed. With the abolition of the domains, the Date joined the new aristocracy and continued to serve the new Meiji regime into the 20th century.

Date Munemoto, the last lord (and first governor) of the Sendai Domain.

The Date were not always on the right side of the law, however. One infamous member of the clan was Junnosuke, who was known for carrying a knife to school and, in 1909, was sentenced to 12 years in prison for shooting a fellow student during a brawl. His sentence was eventually suspended when his lawyer ‘proved’ it was self-defence. In 1916, he left Japan for Manchuria (not yet under Japanese rule at that point), where he joined the Manchurian Independence Movement.

He had a varied career after this, serving in the Border Guards in Korea (then under Japanese control), but in 1923, he seems to have been operating as little more than a bandit in and around the Shandong Peninsula. In 1931, he became a naturalised Chinese citizen, but in 1937, he was at the head of some 4000 soldiers from Manchukuo and took part in the Japanese invasion of China; however, his unit was disbanded in 1939. After the war, he was caught by the Chinese, tried as a war criminal, and shot in 1948, bringing a violent career to a violent end.

Date Junnosuke in the uniform of a Border Guard.

In the interest of ending things on a lighter note, another descendant of the Date clan (a branch of it, anyway) is Date Mikio, one half of the famous comedy duo Sandwichman, who have won many awards and are arguably one of Japan’s most prolific duos, so that’s nice.

The main branch of the Date Clan survives into the modern era as well, with the current head, Date Yasumune, serving as a curator of the Zuihoden Museum, burial place of Date Masamune, and a repository for numerous artefacts related to the clan.

Sources
https://ja.wikipedia.org/wiki/%E4%BC%8A%E9%81%94%E9%A8%92%E5%8B%95
https://en.wikipedia.org/wiki/Date_S%C5%8Dd%C5%8D
https://ja.wikipedia.org/wiki/%E6%96%B0%E7%99%BA%E7%94%B0%E9%87%8D%E5%AE%B6
https://en.wikipedia.org/wiki/Date_Masamune
https://en.wikipedia.org/wiki/Tokugawa_Ieyasu
https://ja.wikipedia.org/wiki/%E4%BC%8A%E9%81%94%E7%B6%B1%E5%AE%97
https://ja.wikipedia.org/wiki/%E4%BC%9A%E6%B4%A5
https://ja.wikipedia.org/wiki/%E4%BA%8C%E6%9C%AC%E6%9D%BE%E5%9F%8E
https://ja.wikipedia.org/wiki/%E8%8B%A5%E6%9D%BE%E5%9F%8E
https://ja.wikipedia.org/wiki/%E6%91%BA%E4%B8%8A%E5%8E%9F%E3%81%AE%E6%88%A6%E3%81%84
https://ja.wikipedia.org/wiki/%E8%B1%8A%E8%87%A3%E7%A7%80%E6%AC%A1
https://ja.wikipedia.org/wiki/%E3%82%B5%E3%83%B3%E3%83%BB%E3%83%95%E3%82%A1%E3%83%B3%E3%83%BB%E3%83%90%E3%82%A6%E3%83%86%E3%82%A3%E3%82%B9%E3%82%BF%E5%8F%B7
https://ja.wikipedia.org/wiki/%E4%BB%99%E5%8F%B0%E8%97%A9
https://ja.wikipedia.org/wiki/%E6%85%B6%E9%95%B7%E9%81%A3%E6%AC%A7%E4%BD%BF%E7%AF%80
https://ja.wikipedia.org/wiki/%E7%9F%B3%E5%B7%BB%E6%B8%AF
https://ja.wikipedia.org/wiki/%E8%B2%9E%E5%B1%B1%E9%81%8B%E6%B2%B3
https://ja.wikipedia.org/wiki/%E4%BC%8A%E9%81%94%E6%94%BF%E5%AE%97
https://ja.wikipedia.org/wiki/%E4%BC%8A%E9%81%94%E6%B0%8F
https://ja.wikipedia.org/wiki/%E4%BC%8A%E9%81%94%E9%A0%86%E4%B9%8B%E5%8A%A9
https://ja.wikipedia.org/wiki/%E4%BC%8A%E9%81%94%E6%B3%B0%E5%AE%97
https://ja.wikipedia.org/wiki/%E3%82%B5%E3%83%B3%E3%83%89%E3%82%A6%E3%82%A3%E3%83%83%E3%83%81%E3%83%9E%E3%83%B3_(%E3%81%8A%E7%AC%91%E3%81%84%E3%82%B3%E3%83%B3%E3%83%93)
https://ja.wikipedia.org/wiki/%E4%BC%8A%E9%81%94%E5%AE%97%E5%9F%BA

December 23, 2025
Kings in the North, Part 2

This is the 50th post on this blog. Well done for getting this far.

In 1565, Date Harumune retired and handed control of the clan over to his son Terumune. Despite this, Harumune held onto the real power, and it wasn’t until 1570, when Terumune accused several of his father’s supporters of treason and had them removed, that he gained actual power.

Date Terumune

Despite this, Terumune continued most of his father’s policies, especially in diplomacy. The alliance with the Ashina Clan was maintained, and Date diplomats reached out to the Hojo, Oda, and Shibata Clans, establishing friendly relations with several of Japan’s most powerful warlords. The Sengoku in Sengoku Jidai literally means ‘country at war’; however, alongside his diplomatic efforts, Terumune showed he wasn’t afraid to throw his weight around if an opportunity presented itself.

In 1578, the death of Uesugi Kenshin presented just such an opportunity, and Terumune dispatched forces to intervene in the internal struggle that followed. The Date intervention was ultimately unsuccessful, largely due to the military skills of the Shibata Clan, vassals of the Uesugi, who fought off the Date in several engagements.

Frustrated, Terumune withdrew, but the Shibata had apparently expected more generous rewards for their service, and in 1581, when it was clear that they would not beforthcoming, the Shibata rebelled. Terumune dispatched his army once again, this time in support of the Shibata, and the conflict within the Uesugi Clan would drag on for years.

Shibata Shigeie, one of the Shibata brothers who gave the Date so much trouble.
_^さどこ – _{^{http://blog.livedoor.jp/sadosado_4hi/archives/8412806.html, CC 表示-継承 4.0, https://commons.wikimedia.org/w/index.php?curid=99877267による}}

Closer to home, the long war against the nearby Soma Clan continued into Terumune’s reign. The Soma were based in southern Mutsu Province (the area of modern Fukushima Prefecture) and had proven to be tenacious opponents of the Date, with neither side ever able to establish a permanent advantage over the other, despite decades of conflict.

In the period of 1582-84, however, the Date finally managed to overcome the Soma. Although the latter clan was not completely subdued, the strategic situation compelled them to make peace in 1584, with the border between the two clans agreed upon by treaty.

Also in 1584, the long-time allies of the Date, the Ashina Clan, fell prey to an internal power struggle, after their lord, Moritaka, was murdered by a retainer (the official reason is said to be ‘due to sodomy’, so make of that what you will). The new head of the clan was just a month old, and so the Ashina were effectively subordinate to the Date, despite nominally remaining independent.

Shortly after this, Terumune retired, handing leadership over to his son, Masamune. Sources disagree on the exact reason for this, with some suggesting that Terumune planned to make his second son head of the Ashina, only to encounter serious opposition from within the Ashina and his own clan, who then forced him to abandon the idea and retire in disgrace. Other sources say that Terumune learned a lesson from the fate of the Ashina and decided to hand over the leadership of the Date to his son while he was still alive, rather than leave the succession to chance.

Date Masamune

Regardless of the reason, Masamune became head of the clan in 1585, and immediately set out to prove that he was not going to do things the same way as his father had. Whilst Terumune had intended to continue the war against the Uesugi, along with his Ashina and Mogami allies, Masamune made peace, without consulting either clan, leading to a sudden and serious decline in relations.

Masamune would definitively end the alliance shortly afterwards when he invaded Ashina territory, which the Ashina, unsurprisingly, interpreted as a hostile act. The invasion would prove to be a back-and-forth affair, with the Ashina successfully repelling the Date’s first attacks only to be defeated by a second wave, led by Masamune himself.

In late 1585, the Ashina asked for a truce, and a peace was mediated by Terumune and his uncle, Sanemoto. The negotiations would prove to be a ruse, however, as Ashina forces kidnapped Terumune at sword point and tried to escape back to their own territory. What happened next is a matter of debate; some sources state that Terumune, seeing that he couldn’t escape, ordered the pursuing Date forces (his own men) to open fire with their bows, killing the entire party, including Terumune.

Another source suggests that the Ashina, trapped by the Date pursuit, killed Terumune themselves, and were then cut down. A third source (written later) states that Masamune himself was responsible for Terumune’s death, and may have orchestrated the whole thing to get rid of his father. Though the exact circumstances will never be known, Terumune’s death also signalled the end of serious attempts to end the local conflicts through negotiation.

Shortly after his father’s somewhat controversial death, Masamune continued the war. In January 1586, he laid siege to Nihonmatsu Castle (in the city of the same name, in modern Fukushima). At this time, an army led by the Satake Clan, from Hitachi province (to the south), arrived to relieve the castle. The Date were defeated at the Battle of Hitotori Bridge, and Masamune himself was badly wounded before a rearguard action allowed him to escape.

The restored Nihonmastu Castle.
_{^{baku13 – 投稿者自身による著作物, CC BY-SA 2.1 jp, https://commons.wikimedia.org/w/index.php?curid=11354374による}}

The defeat was evidently not serious, because only a few months later, after the Satake had withdrawn, Masamune tried again, once again besieging Nihonmatsu Castle, forcing its surrender in July. Not long after this, he negotiated a peace with the Satake with the intention of focusing his efforts on finishing off the Ashina. This peace was short-lived, even by the standards of the day, as a succession crisis within the Ashina Clan drew the attention of the Satake, who supported a rival candidate to Masamune’s preferred choice.

Masamune interpreted this as the Satake intending to bring the Ashina under their control, which would have put the Date in an extremely vulnerable situation. In response, he declared his intention to wage a full-scale war against both the Ashina and Satake. In 1587, Toyotomi Hideyoshi, by now acting as regent, issued an order that all private wars should halt, an order that Masamune, for now at least, ignored.

Masamune initially had reason to regret his continued belligerence. In 1588, his old enemies, the Mogami Clan, took advantage of Masamune being distracted elsewhere and invaded Date territory at the same time as the Ashina Clan attacked in the south. After defeats at the Battle of Osaki and then at Koriyama, Masamune was obliged to seek peace with both clans, stabilising the situation in the short term.

In 1589, the peace with the Ashina Clan broke down once again, with Masamune invading the Aizu region (in the west of modern Fukushima). Masamune won a decisive victory at the Battle of Suriagehara in July 1589, causing the Ashina to flee their home castle at Kurokawa (modern Aizuwakamatsu) and seek help from the Satake. The Satake were obeying Hideyoshi’s peace order, however, and no help was forthcoming. Shortly after this, Masamune moved his base to Kurokawa Castle, and when a second order from Hideyoshi arrived, threatening direct intervention, Masamune took the opportunity to make peace.

Fukushima Prefecture, where Aizu is located.

A year later, Hideyoshi ordered the Date to join him in his attack on the Hojo Clan at the siege of Odawara. This put Masamune in a difficult spot, since the rule of his father, Terumune, the Date and Hojo had been nominal allies, and when Hideyoshi’s order arrived, it wasn’t immediately clear which side Masamune would join. Masamune eventually marched in support of Hideyoshi, but the regent wouldn’t forget Date disobedience of his peace order.

Sources
https://ja.wikipedia.org/wiki/%E4%BC%8A%E9%81%94%E6%94%BF%E5%AE%97
https://ja.wikipedia.org/wiki/%E8%B1%8A%E8%87%A3%E7%A7%80%E6%AC%A1
https://ja.wikipedia.org/wiki/%E6%91%BA%E4%B8%8A%E5%8E%9F%E3%81%AE%E6%88%A6%E3%81%84
https://ja.wikipedia.org/wiki/%E8%8B%A5%E6%9D%BE%E5%9F%8E
https://ja.wikipedia.org/wiki/%E4%BA%8C%E6%9C%AC%E6%9D%BE%E5%9F%8E
https://ja.wikipedia.org/wiki/%E4%BD%90%E7%AB%B9%E6%B0%8F
https://en.wikipedia.org/wiki/Hitachi_Province
https://en.wikipedia.org/wiki/Aizu
https://ja.wikipedia.org/wiki/%E4%BC%8A%E9%81%94%E6%B0%8F
https://ja.wikipedia.org/wiki/%E4%BC%8A%E9%81%94%E8%BC%9D%E5%AE%97

December 19, 2025
Kings in the North

Just a quick note: Date is pronounced “Da-Tay”.

The mon of the Date Clan.

Like many of the great clans of the Sengoku period, the Date’s exact origins are subject to a fair amount of mythologising. The family originally claimed to be descended from the prestigious Fujiwara Clan, but that doesn’t have very much supporting evidence, and most modern scholars agree that the clan’s origins were far more humble.

That isn’t to say they didn’t earn their place, however. The first attested ancestor of the Clan was Date Tomomune, who was rewarded for services in battle with the manor of Date in modern Fukushima Prefecture. Tomomune himself is a bit of a murky figure (as they all seem to be), and there are still unanswered questions about his origins and even his identity, but for the sake of simplicity, we’ll agree with the Date’s own genealogy and start the story of the clan with him.

Similar to many other clans in the period, the Date were not tied down to a single geographic location, and branches of the clan would pop up all over Japan as their fortunes rose and fell. For our purposes, it is the Date clan of Mutsu Province that we’ll be focusing on.

Mutsu Province.
_{^{By Ash_Crow – Own work, based on Image: Provinces of Japan.svg, CC BY 2.5, https://commons.wikimedia.org/w/index.php?curid=1690724}}

The Date largely supported the Kamakura Shogunate, founded by Minamoto no Yoritomo, and in the 13th century, the Lord of the Date is said to have been living in Kamakura (the political capital). However, when the Shogunate was overthrown, the Date threw in their lot with the Emperor and would continue to support the Imperial throne even after the establishment of the Ashikaga Shogunate in 1336.

This support would backfire, however, as the Date, in support of the Southern Court, were defeated by forces of the Northern Court, loyal to the new Ashikaga Shoguns, and ultimately obliged to switch sides. Beginning in the 1380s, the Date would set about restoring their strength by attacking rival clans in their home region. As was common at the time, these local conflicts were framed as part of the larger Northern-Southern Conflict (the Nanboku-cho Period), but were, in reality, private wars that the central authorities were powerless to direct.

Later, when the power of the Ashikaga Shoguns was beginning to fracture, the Date would use the conflict between the government in Kyoto and the Kamakura kubo to further enhance their own power. Though nominally under the jurisdiction of Kamakura, the Date would appeal directly to Kyoto to serve as their vassals. The Shogunate agreed, and when open conflict between Kyoto and Kamakura broke out in the 1480s, the Date were in a prime position to take advantage.

The territories under the nominal jurisdiction of the Kamakura Kubo.

An example of how strong the Date had become can be found in records from 1483, in which the Lord of the Date dispatched gifts to the court in Kyoto, including 23 swords, 95 horses, 380 ryo of gold dust, and 57,000 coins. This was an extraordinary fortune at the time, and seems to have led to the acceptance by the court of the Date’s position of the strongest (or at least richest) clan in the North.

Despite their wealth and power, the Date were not the most prestigious clan in the region. That honour went to the Osaki, who were faithful to the Shogunate in Kyoto and were long established. As was common during the later 15th century, however, the Osaki had a prestigious name, but their actual power was crumbling. Though nominally their subordinates, the Date would intervene in a power struggle within the Osaki Clan in 1488, bringing an end to the conflict, but effectively reducing the Osaki to vassal status in the process.

Another rival to the Date was the Mogami Clan from neighbouring Dewa Province. The clans would clash repeatedly, but in 1514, Date Tanemune would inflict a decisive defeat on the Mogami at Hasedo Castle. Shortly after this, he would marry his sister to the defeated Lord of the Mogami, effectively binding the two clans together. This would prove unpopular with the remaining Mogami vassals, and when their Lord died in 1520, and the Date attempted to take direct control, they rebelled.

The site of Hasedo Castle as it appears today.
_{^{Koda6029 – 投稿者自身による著作物, CC 表示-継承 4.0, https://commons.wikimedia.org/w/index.php?curid=124663430による}}

In defeating the rebellion, Tanemune was able to establish Date control over most of eastern Dewa Province, further expanding his clan’s power and prestige. In recognition of this, in 1522, the Shogunate appointed Tanemune shugo (governor) of Mutsu Province (the Date’s home province, remember). Tanemune was not satisfied, however, as he had apparently sought the title of tandai.

The exact distinction between shugo and tandai is a little unclear, as the titles often overlapped, but essentially, a shugo was the governor of a single province, whereas a tandai was the Shogun’s representative over a wider area. Although the power and prestige of the Shogunate were at a low ebb by this point, the fact remained that tandai was a more prestigious title, and the Shogunate’s refusal to bestow it on Tanemune was seen as a proverbial slap to the face.

Tanemune responded to this but charting his own course, although the snub is probably just a convenient excuse for what he was going to do anyway; by the early 16th century, Shogunate power was really more of a concept, and the Date were one of many powerful clans who realised that they could largely do as they pleased.

Date Tanemune.

Over the next 20 years, Tanemune would work to consolidate his clan’s control over the North, further absorbing the Osaki and Mogami clans, as well as extending physical control over most of Mutsu and Dewa Provinces. Despite his successes, all was not well within the clan; Tanemune was in conflict with his eldest son, Harumune. The exact nature of the conflict is complicated, but it got so bad that in June 1542, Harumune ambushed his father whilst the latter was out hunting, imprisoning him in a nearby castle from which Tanemune swiftly escaped (or was rescued, depending on the source)

What followed was a six-year conflict which saw the Date severely weakened, and several of their recently conquered vassals breaking free, including the Osaki and the Mogami. Eventually, the mediation of the Shogun brought about an official peace, but in reality, the feud didn’t end, and although Harumune would take his place as the de facto head of the clan, Tanemune, despite becoming a monk, remained an enormously influential figure.

Harumune’s reign would be occupied with reestablishing Date power. The situation was far from ideal, however, and he was eventually forced to confirm many of the concessions that had been granted to vassals by both sides, signing away territory and privileges in exchange for obedience.

Date Harumune

One upside for Harumune was the fact that he had no fewer than eleven children, six sons and five daughters, who would be useful pawns in returning former vassals to the fold. All of his daughters were married either to powerful clans, securing alliances, or to senior vassals, ensuring their loyalty, and by the 1560s, the Date’s position was once again strong.

In 1565, Harumune retired and handed control to his son, Terumune, although, as was common, he retained all the actual power. A year later, the Ashina Clan attacked the Nikaido, who were allied with the Date through the marriage of one of Harumune’s daughters. The Date intervened but were defeated, and when the Nikaido surrendered shortly afterwards, peace between the Date and Ashina was secured through another marriage, this time between the Lord of the Ashina’s eldest son and Harumune’s fourth daughter.

Harumune apparently opposed this marriage, and in response, Terumune entered into a secret agreement with the Ashina, in which they would agree to support him in the event of an outbreak of conflict between father and son. The feud between father and son would only be resolved in 1570, when Terumune removed several retainers who had facilitated Harumune’s rule from ‘behind the curtain’. With this, the relationship seems to have improved, as Harumune was now effectively powerless anyway.

Like most of his contemporaries, Terumune’s reign would be dominated by war, but we’ll talk about that next time.

Sources
https://en.wikipedia.org/wiki/Mutsu_Province
https://ja.wikipedia.org/wiki/%E4%BC%8A%E9%81%94%E6%B0%8F
https://ja.wikipedia.org/wiki/%E6%9C%80%E4%B8%8A%E6%B0%8F
https://ja.wikipedia.org/wiki/%E4%BC%8A%E9%81%94%E7%A8%99%E5%AE%97
https://ja.wikipedia.org/wiki/%E4%BC%8A%E9%81%94%E6%88%90%E5%AE%97
https://ja.wikipedia.org/wiki/%E5%A4%A7%E5%B4%8E%E6%B0%8F
https://ja.wikipedia.org/wiki/%E4%BC%8A%E9%81%94%E5%B0%9A%E5%AE%97
https://ja.wikipedia.org/wiki/%E4%BC%8A%E9%81%94%E5%AE%97%E9%81%A0
https://ja.wikipedia.org/wiki/%E4%BC%8A%E9%81%94%E9%83%A1
https://ja.wikipedia.org/wiki/%E5%B8%B8%E9%99%B8%E5%85%A5%E9%81%93%E5%BF%B5%E8%A5%BF
https://ja.wikipedia.org/wiki/%E4%BC%8A%E9%81%94%E6%9C%9D%E5%AE%97
https://en.wikipedia.org/wiki/Dewa_Province
https://ja.wikipedia.org/wiki/%E4%BC%8A%E9%81%94%E6%99%B4%E5%AE%97
https://ja.wikipedia.org/wiki/%E4%BC%8A%E9%81%94%E8%BC%9D%E5%AE%97

December 16, 2025
The Shimazu, Part 2

By 1582, the Shimazu were once again masters of southern Kyushu and had recently defeated the rival Otomo Clan so comprehensively that they effectively ceased to be an obstacle to Shimazu dominance of the whole island. This ambition would be curbed by the intervention of Oda Nobunaga, who wanted to get the Otomo to join his attack on the Mori Clan.

The situation in 1582. The Shimazu are in blue, and the Otomo in purple. The Mori are in yellow, and Oda Nobunaga is the big red blob in the middle.
_{^{By Alvin Lee – Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=39198356}}

Nobunaga’s plans, along with his life, would be cut short in the Honnoji Incident in June 1582, and the Shimazu once again found themselves as the strongest clan on Kyushu. In the far north-west of the island, close to the modern city of Nagasaki, lay the base of the Ryuzoji Clan. For generations, the Ryuzoji had been a secondary clan in the region. However, under the leadership of Ryuzoji Takanobu, they had expanded their power to control the whole of Hizen Province (modern Nagasaki and Saga Prefectures), and although they had nominally been subordinates of the Otomo Clan, the aftermath of the Battle of Mimikawa in 1578 (which the Otomo lost) gave the Ryuzoji the opportunity to expand even further. (They are in the light-green on the map above).

It was inevitable that the Shimazu and Ryuzoji would clash, and in 1584, a member of the Arima Clan wrote to Shimazu Yoshihisa, requesting his aid against the Ryuzoji. This was a convenient excuse to do what he probably would have done anyway, and Yoshihisa dispatched an army under his brother Iehisa. What followed was a lightning campaign in which the Shimazu, despite being outnumbered more than three-to-one, engaged and defeated the Ryuzoji at the decisive Battle of Okitanawate in May 1584.

This proved to be yet another decisive victory for the Shimazu. Not only did they defeat the Ryuzoji army, Takanobu, but the lord of the clan was also killed, cutting the head off the proverbial snake. The Ryuzoji had expanded rapidly, and their control collapsed just as quickly. Clans who had been forced to submit quickly switched sides to the Shimazu, and any holdouts were destroyed in short order.

In 1586, Yoshihisa turned his attention to the remnants of the Otomo Clan, invading Bungo Province and crushing the final remnants of what had once been Kyushu’s pre-eminent clan. Yoshihisa might have had time to reflect on the fleeting nature of power in that era, but he wouldn’t have had long. No sooner did the Shimazu deal the final blow to the Otomo than the last holdouts of that clan appealed to the new power in Japan for help, Toyotomi Hideyoshi.

The situation in 1586, after Toyotomi Hideyoshi secured power, and the Shimazu came so close to unifying Kyushu.
_{^{By Alvin Lee – Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=39214208}}

The Shimazu were at the height of their power, and it is perhaps no surprise that, when Hideyoshi order them to cease their attacks on the Otomo, they refused. Yoshihisa went even further, when he suggested that the Shimazu, and old and storied clan, had no need to accept an ‘upstart’ like Hideyoshi as regent. Hideyoshi had been born a peasant, but he was the most powerful warlord in Japan by that point, and Yoshihisa would come to regret the disrespect.

When it became clear that Hideyoshi meant to invade Kyushu, the Shimazu doubled their efforts to crush the Otomo and secure the whole island. They rightly guessed that any Otomo holdouts would be used by Hideyoshi’s forces as a base for any campaign. Though they would ultimately be unable to fully subjugate the Otomo, the Shimazu’s confidence seemed to have been well placed when, in early 1587, Chosokabe forces, under Hideyoshi’s orders, invaded Bungo province and were heavily defeated at the Battle of Hetsugigawa.

Shimazu celebrations would be short-lived, however. Hideyoshi, reportedly enraged by the ease with which the Shimazu had apparently defeated the initial invasion, mustered a force of between 250,000 and 300,000 men (reports vary), possibly the largest army seen in Japan up to that time. Throughout the spring and summer of 1586, this huge force steamrolled the Shimazu. There were instances of brave resistance, but the writing was on the wall, and in June, the Shimazu sued for peace.

Taiheiji Temple in modern Kagoshima, where Shimazu Yoshihisa met with Toyotomi Hideyoshi, and a peace was agreed.
_{^{Sakoppi – 自ら撮影, CC 表示 3.0, https://commons.wikimedia.org/w/index.php?curid=12570199による}}

The terms were harsh, but ultimately secured the survival of the clan. Hideyoshi demanded that the Shimazu give up control of almost the whole of Kyushu, essentially wiping out centuries of conquest and expansion. In return, the Shimazu were confirmed as lords of Satsuma province, and later, after further negotiations, Osumi as well.

The Shimazu would prove to be somewhat unreliable vassals. When Hideyoshi invaded Korea in 1592, he ordered all feudal lords to commit troops. The Shimazu were apparently slow to comply with this order, leading Hideyoshi to suspect they were disloyal (which they probably were, having been only recently conquered)

The Shimazu would eventually obey and dispatch troops to Korea, but it appears that Yoshihisa had been replaced as head of the clan in the eyes of Hideyoshi, as formal letters recognising Shimazu control of their provinces were written in the name of Shimazu Iehisa, Yoshihisa’s younger brother, though it appears that Yoshihisa retained the actual power.

Shimazu Iehisa (sometimes called Yoshihiro), the nominal head of the Shimazu after Hideyoshi’s invasion of Kyushu.

Hideyoshi’s death and the end of the war in Korea refocused the realm’s attention back home, as Hideyoshi’s son and heir was just a child. The Shimazu would not be members of the Council of Regents, but when the final rupture occurred in 1600, and war became inevitable, Shimazu Iehisa (nominal head of the clan) was in Kyoto and swore loyalty to the Western (or pro-Toyotomi) army.

This move was apparently not supported by his older brother and the wider Shimazu clan, as when Iehisa requested reinforcements, he received none. This might have been a deliberate ploy by the Shimazu to play both sides, but it’s also possible that an outbreak of fighting in Kyushu caused the Shimazu to focus their efforts closer to home.

The fighting was relatively small-scale and was nominally between supporters of the Toyotomi and Tokugawa Ieyasu (who had just won the decisive Battle of Sekigahara). In reality, this was probably an example of a breakdown in central authority being taken advantage of by local warlords. Unlike in previous eras, however, central control was swiftly reestablished. After his victory at Sekigahara, Ieyasu turned his attention to subduing the rest of the realm, Kyushu included.

Tokugawa Ieyasu.

A planned campaign against the Shimazu was cancelled in favour of negotiations that lasted nearly two years. Ieyasu suggested that Yoshihisa travel to Kyoto in person, but Yoshihisa always had an excuse not to go; he was ill, the roads were bad, the weather was awful, he hadn’t got enough money, etc. Finally, in 1602, Ieyasu, who apparently had no real appetite for a campaign in Kyushu, confirmed Shimazu control of Satsuma and Osumi Provinces after Yoshihisa’s brother, Iehisa, went to Kyoto in his place (some sources say Yoshihisa actually opposed this idea, only approving it after the fact, when his brother had already departed)

The Shimazu would be largely left in peace in the decades that followed. In 1609, Iehisa, but now more or less dejure lord of the Shimazu, received permission from the Tokugawa to invade the Ryukyu Kingdom (modern Okinawa). This meant that the Shimazu became the only clan to control a foreign kingdom, and meant that, when Japan entered its period of isolation (Sakoku), the Shimazu were one of the few who still had access to the outside world.

These contacts would grant the Shimazu an unusual level of economic strength in the Edo period, and this, combined with some strategic marriages into the Tokugawa, meant that the clan, despite (or perhaps because of) its distance from Edo (modern Tokyo), became one of the richest and most powerful of the era.

A Ryukyu tributary mission to China. The relationship between Ryukyu and China allowed the Shimazu to maintain indirect trade links with mainland Asia.

This proved to be important in the 19th century, when the irresistible tide of modernisation swept Japan after the first American, but later, other powers sought to take advantage of Japan’s weak position for their own ends. It would be the Shimazu (better known as Satsuma Domain by then) under their leader Nariakira, who were amongst the first to grasp the potential for Western-style industrialisation and warfare.

Satsuma Domain would be at the vanguard of the Meiji Restoration, with its alliance with the Mori clan of the Choshu Domain proving to be the decisive factor in the brief, but bloody Boshin War that saw the Tokugawa overthrown and Imperial rule reestablished.

The Shimazu themselves would endure the tumultuous years of the late 19th and 20th centuries, and the family survives today, with the 33rd head of the clan, Shimazu Tadahiro, serving as CEO of the Shimazu Corporation, which works to promote not only the cultural legacy of the Shimazu family, but also tourism and business development in and around Kagoshima, the traditional heart of the Satsuma Domain.

Sources
https://ja.wikipedia.org/wiki/%E5%B3%B6%E6%B4%A5%E7%BE%A9%E4%B9%85
https://ja.wikipedia.org/wiki/%E5%B3%B6%E6%B4%A5%E7%BE%A9%E5%BC%98
https://ja.wikipedia.org/wiki/%E5%B3%B6%E6%B4%A5%E6%B0%8F#
https://ja.wikipedia.org/wiki/%E5%B3%B6%E6%B4%A5%E5%BF%A0%E8%A3%95
https://ja.wikipedia.org/wiki/%E5%B3%B6%E6%B4%A5%E8%88%88%E6%A5%AD
https://ja.wikipedia.org/wiki/%E5%B3%B6%E6%B4%A5%E6%96%89%E5%BD%AC
https://ja.wikipedia.org/wiki/%E6%A0%B9%E7%99%BD%E5%9D%82%E3%81%AE%E6%88%A6%E3%81%84
https://ja.wikipedia.org/wiki/%E4%B9%9D%E5%B7%9E%E5%B9%B3%E5%AE%9A
https://ja.wikipedia.org/wiki/%E6%88%B8%E6%AC%A1%E5%B7%9D%E3%81%AE%E6%88%A6%E3%81%84
https://ja.wikipedia.org/wiki/%E6%B2%96%E7%94%B0%E7%95%B7%E3%81%AE%E6%88%A6%E3%81%84
https://ja.wikipedia.org/wiki/%E9%BE%8D%E9%80%A0%E5%AF%BA%E9%9A%86%E4%BF%A1
https://en.wikipedia.org/wiki/List_of_daimy%C5%8Ds_from_the_Sengoku_period

December 11, 2025
The Shimazu, Part 1

Last time we looked at Shikoku, the so-called ‘four provinces’, well, how about an island of nine provinces? That’s right, Kyushu, the third largest of Japan’s main islands, is so called because in the pre-modern period it was home to nine whole provinces, which means, as names go, it’s not terribly creative, but what can you do?

Kyushu.
_{^{By TUBS – This vector image includes elements that have been taken or adapted from this file:, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=16385933}}

In ancient times, Kyushu had been the centre of cultural, economic, and social development in Japan, as its close proximity to Korea, and by extension China, made it the logical landing site for innovations as widespread as rice farming and written language. The island would also be the focus of two ultimately unsuccessful Mongol invasions in the 13th Century, and the Shogunate administration there would continue to be important until the decline of central authority in the 15th Century left Kyushu, much like the rest of the realm, effectively independent.

Into this power vacuum stepped several powerful clans, with the most prominent arguably being the Ouchi, Otomo, and Shimazu. Though the Ouchi and Otomo would play important roles of their own in the story of the Sengoku Period, it is the Shimazu that we will be focusing on.

The exact origins of the Shimazu name aren’t entirely clear, but the first figure to take the name was Tadahisa, who was made lord of the Shimazu Manor in southern Kyushu in 1185. Tadahisa himself is something of a mysterious figure, with various conflicting reports of his origins, parentage, and even his name, but what is clear is that the Shimazu were well established in southern Kyushu by the 13th century, and would use it as their base going forward.

Shimazu Tadahisa, the first “Lord” Shimazu.

Tadahisa’s son, Tadatoki, seems to have been an accomplished military leader, as he was appointed the shugo (military governor) of Satsuma, Osumi, and Hyuga Provinces, all of southern Kyushu in effect. He was also granted numerous prestigious lands and titles around the realm, but it was his Kyushu holdings that would be the most important for his descendants.

The Shimazu’s fortunes would ebb and flow over time, but the distance of their lands from the centre of power in Kyoto meant that they were often able to weather the storms of early Medieval Japan. They were not immune from the ever-present problem of internal conflict, however, and by the time of the Onin War in 1467, the Shimazu were weak, divided, and vulnerable.

It would be Shimazu Tadayoshi (1492-1568) who would begin to turn the fortunes of the clan around. Originally from the Isaku Clan (a branch of the Shimazu), Tadayoshi had a difficult start to life. His father, Yoshihisa, was apparently murdered by a stable hand when Tadayoshi was just two, and his grandfather was killed in battle in 1500. Following this, Tadayoshi’s mother, Lady Baiso, agreed to marry the lord of another branch of the Shimazu, on the condition that Tadayoshi be adopted as heir to both branches. The lord in question was apparently so keen on Lady Baiso that he agreed.

Shimazu Tadayoshi.

Tadayoshi proved to be an enlightened and capable ruler, taking inspiration from Zen teachings and humanitarian principles. He was a popular leader, as he genuinely cared for the needs of his retainers and the welfare of his territory, but his son, Takahisa, would prove to be greater still. In 1526, following the deaths in quick succession of both his sons, the head of the main branch of the Shimazu Clan, Katsuhisa, turned to Tadayoshi (renowned for his learning and upright conduct) for a solution to the succession issue.

Tadayoshi had Takahisa adopted by the Lord of the Shimazu. In November 1526, Katsuhisa handed over control of the Shimazu Clan to Takahisa and retired to a monastery. Tadayoshi became a monk himself shortly afterwards and would go on to play a significant role in aiding his son in reestablishing Shimazu power in southern Kyushu.

Shimazu Takahisa.

Things are never quite that simple, however, and Takahisa’s accession to the leadership of the Shimazu was opposed by several powerful retainers, some of whom also claimed the right to lead. Katsuhisa himself also seems to have expressed some regret about handing over power, and in June 1527, an army was raised which drove Takahisa out, and had Katsuhisa returned as the shugo.

The fighting would go back and forth for a while after this, despite unsuccessful efforts to arrange a reconciliation in 1529. Katsuhisa proved to be an unpopular lord, however, apparently being more focused on ‘vulgar entertainment’ than the business of ruling. Though this did not automatically translate into support for Takahisa, the division amongst his enemies handed him the initiative.

Starting in 1533, Takahisa would lead a series of counter-attacks which eventually saw him establish control over most of Satsuma Province, and in 1539, the decisive Battle of Murasakihara saw Takahisa drive out his primary rivals, though it wouldn’t be until 1552 that he was finally recognised as the shugo of Satsuma Province by the Shogunate, 26 years after he had first assumed the mantle.

Satsuma Province, home of the Shimazu Clan.
_{^{By Ash_Crow – Own work, based on Image:Provinces of Japan.svg, CC BY 2.5, https://commons.wikimedia.org/w/index.php?curid=1691755}}

Takahisa had long hoped to reestablish Shimazu control of the three provinces held by his ancestors, and he would lead campaigns into neighbouring Osumi province from 1554 to 1556, which would allow him to establish a foothold in the province from which further expansion could be launched.

Though Takahisa would prove to be a successful warrior, he was also known for his outward-looking attitude towards foreigners. The Shimazu had long had trade with Ming China, largely through intermediaries in the Ryukyu Islands (modern Okinawa), and after Portuguese merchants arrived in Japan, Takahisa was one of the first lords to welcome them to his domains, and perhaps one of the first to employ firearms in battle.

He would also go some way to establishing Christianity in Japan, as he welcomed Francis Xavier into his territory in 1549, though this would ultimately prove a short-lived association, due to backlash from conservative elements amongst the Buddhist and Shinto priesthoods.

A later depiction of a Portuguese trading ship in Japanese waters.

Takahisa would eventually retire to a monastery in 1556, handing control of the Shimazu over to his son, Yoshihisa, who also inherited his father’s ambitions to regain control of the three provinces of Satsuma, Osumi, and Hyuga. Yoshihisa had actually joined his father’s campaign in Osumi, making his ‘debut’ in 1554, and after inheriting the leadership from his father, he would continue the campaigns to fully pacify Satsuma and expand Shimazu holdings into the neighbouring provinces.

Satsuma would come under his complete control in 1570. In 1572, a rival clan from Hyuga Province would invade Shimazu territory, only to be defeated in short order at the Battle of Kizakihara, with the Shimazu forces being led by Yoshihisa’s highly capable younger brother, Yoshihiro. It is said that the Shimazu, despite being outnumbered 10 to 1, launched an aggressive attack against the enemy, which saw several key leaders killed and over 500 enemy deaths (counted in heads taken after the battle).

A later depiction of a head viewing (kubi-jikken), a common practice among Samurai, in which the heads of defeated enemies would be presented to lords, or otherwise publicly displayed.

This victory allowed Yoshihisa to focus on Osumi Province, which he was able to fully conquer by the end of 1573. Then in 1576, he captured the strategically important Takahara Castle, held by the powerful Ito Clan of Hyuga. The fall of Takahara led to a domino effect in which the remaining 48 castles of the Ito Clan were either conquered or defected to the Shimazu. Not long after, the head of the Ito Clan, Yoshisuke, fled Hyuga, and the long-dreamt-of reunification of the three provinces was achieved.

Almost as soon as the dust had settled, however, the powerful Otomo Clan, who controlled several provinces in North-Eastern Kyushu, invaded, nominally in support of the exiled Yoshisuke, but more likely in an opportunistic attempt to expand their own territory. A huge army of some 43,000 men crossed into Hyuga Province in October 1578 and laid siege to Takashiro Castle. The Shimazu under Yoshihisa could muster only 20,000 men in response, but they took advantage of poor coordination amongst the Otomo, dealing with the invaders piecemeal.

The campaign culminated in the Battle of Mimikawa (which was actually fought nearly 20 miles from the eponymous river), in which Yoshihisa employed a series of feigned retreats, breaking the Otomo Army (which still enjoyed a numerical advantage) down, and eventually winning a victory that was so comprehensive the Otomo effectively ceased to be serious rivals.

The war wouldn’t end at Mimikawa, however, and in 1580, Oda Nobunaga began negotiations between the Otomo and Shimazu, hoping to bring an end to the war, since he wanted the Otomo to join his upcoming campaign against the Mori. The negotiations were apparently successful, as Yoshihisa even went so far as to recognise Nobunaga as his ‘lord’, and planned to join the attack on the Mori as well.

The situation on the eve of Nobunaga’s death in 1582. The Shimazu lands are blue, in southern Kyushu.
_{^{By Alvin Lee – Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=39198356}}

As we already know, Nobunaga’s death at the Honnoji incident in June 1582 put an end to those plans, but the weakened state of the Otomo and the fact that the peace deal no longer applied meant that the Shimazu were able to defeat or force the defection of several former Otomo retainers, increasing their own power and control over southern Kyushu.

The campaign to unify the entire island would go on, but we’ll look at that next time.

Sources
https://ja.wikipedia.org/wiki/%E5%B3%B6%E6%B4%A5%E7%BE%A9%E4%B9%85
https://ja.wikipedia.org/wiki/%E8%80%B3%E5%B7%9D%E3%81%AE%E6%88%A6%E3%81%84
https://ja.wikipedia.org/wiki/%E5%A4%A7%E5%8F%8B%E6%B0%8F
https://ja.wikipedia.org/wiki/%E5%B3%B6%E6%B4%A5%E7%BE%A9%E5%BC%98
https://ja.wikipedia.org/wiki/%E5%B3%B6%E6%B4%A5%E8%B2%B4%E4%B9%85
https://ja.wikipedia.org/wiki/%E5%B3%B6%E6%B4%A5%E5%BF%A0%E8%89%AF
https://ja.wikipedia.org/wiki/%E6%A2%85%E7%AA%93%E5%A4%AB%E4%BA%BA
https://ja.wikipedia.org/wiki/%E8%96%A9%E6%91%A9%E5%9B%BD
https://en.wikipedia.org/wiki/Shimazu_Takahisa
https://ja.wikipedia.org/wiki/%E5%B3%B6%E6%B4%A5%E5%BF%A0%E4%B9%85
https://ja.wikipedia.org/wiki/%E5%B3%B6%E6%B4%A5%E6%B0%8F
https://en.wikipedia.org/wiki/List_of_daimy%C5%8Ds_from_the_Sengoku_period

December 9, 2025
(No longer) Lords of the Four Provinces

Last time, we looked at how the Chosokabe rose from barely holding a single castle to becoming effective masters of the whole of Shikoku. In 1582, it had looked like they were about to be invaded and (probably) conquered by Oda Nobunaga, but his sudden death at the Honnoji Incident in June 1582 granted the Chosokabe a brief reprieve.

The mon of the Chosokabe Clan.
_{^{百楽兎 – 投稿者自身による著作物, CC 表示-継承 3.0, https://commons.wikimedia.org/w/index.php?curid=9987939による}}

Between 1582 and 1585, they completed their conquest of Shikoku, although exactly how much control they really exerted is still debated by historians, with some suggesting that Shikoku was conquered and pacified, but others making the case that Chosokabe control outside of Tosa Province was tenuous.

Regardless of the nature of Chosokabe’s control of Shikoku, it would prove to be brief. In the spring of 1585, Hashiba Hideyoshi, fresh from defeating the last of his rivals to the mantle of Nobunaga’s successor, turned his attention to Shikoku. Hideyoshi ordered the Chosokabe to hand over Iyo and Sanuki Provinces, effectively ceding the northern half of Shikoku to him.

Toyotomi Hideyoshi, who would eventually become master of Japan.

The Lord of the Chosokabe, Motochika, tried to negotiate, offering just Iyo Province. Hideyoshi was not a man to be bargained with, however, and in response to what he saw as Chosokabe’s defiance, he dispatched an army of some 100,000 men under the overall command of his brother, Hidenaga.

Shikoku was attacked from three sides: Sanuki and Awa by Hidenaga’s army, and Iyo by the Mori who had recently submitted to Hideyoshi and were keen for a chance to prove their loyalty. Attacked on multiple fronts and facing overwhelming numbers, the Chosokabe did not resist for long. At the end of July, after already having lost Awa Province, Motochika surrendered.

The terms were harsh, but not as bad as they might have been. Hideyoshi allowed the Chosokabe to keep control of Tosa Province, but the other three were divided amongst Hideyoshi’s vassals. In 1586, the Chosokabe would join Hideyoshi’s invasion of Kyushu, and though the campaign itself would be successful, Motochika’s heir, Nobuchika, was killed in battle.

Overcome with grief, Motochika is supposed to have tried to kill himself, only being dissuaded at the last minute by his vassals. Not long after this, he relocated the base of the clan to what is now Kochi Castle, and in 1588, he named his fourth son, Morichika, as the new heir.

Kochi Castle as it appears today.
^{_{By Taisyo – photo taken by Taisyo, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=2157936}}

In 1590, the Chosokabe again went to war in the service of Hideyoshi, this time dispatching naval forces to attack the Hojo Castle at Shimoda with 10,000 men. The garrison of 500 held out for nearly two months, but it was eventually taken, and with it, the Chosokabe contribution to the wider Odawara Campaign came to an end.

In 1591, Motochika moved his base from Kochi Castle to a position at Urado (still within the modern city of Kochi). Some sources say this was because of the unfavourable location of the first castle (it was prone to flooding), whilst others suggest it was a strategic move, with Urado serving as the main base of the Chosokabe Navy, which took part in Hideyoshi’s long and ultimately unsuccessful invasions of Korea from 1592-1598.

In 1596, the San Felipe Incident occurred when a Spanish Galleon (the San Felipe, hence the name) was shipwrecked off the coast of Tosa and brought into the harbour at Urado. We’ll focus on this incident specifically in a later post, but the short version is that Motochika confiscated the remaining cargo of the Galleon, and when officials from Hideyoshi arrived in Kochi to take possession of the goods, the captain of the Galleon heavily implied that the presence of Christians in Japan was the precursor to a Spanish Invasion, explaining that that was how the Spanish had managed to conquer such a large part of the globe.

Hideyoshi had initially issued orders expelling Christian priests from Japan in 1586, but it had been unenforced before now. When news of the supposed Spanish invasion reached him, Hideyoshi was horrified, and in 1597, he had 26 Christians (including one passenger from the San Felipe) marched from Kyoto to Nagasaki (the centre of Christianity in Japan) and had all 26 crucified on a hill overlooking the city.

A 19th Century depiction of the executions. The Japanese are wrongly portrayed with Chinese clothing and weapons.

Motochika’s role in the persecution that followed is not clear, though Christianity had never been particularly strong on Shikoku, as the Chosokabe were largely opposed to foreigners in Japan, so it’s not hard to imagine he would have had no qualms about expelling them from his territory, even if he was not actively involved in the wider campaign.

Hideyoshi’s death in 1598 would threaten the fragile peace he had forged, as his son and heir was just a boy, and a council of five regents was appointed to rule in his stead. Though Motochika was not a member of the council, he was still a man of influence, and in 1599, he was in Kyoto for an audience with Toyotomi Hideyori (Hideyoshi’s son) when he fell seriously ill.

When it became clear that he wasn’t going to get better, he made his will, leaving control of the Chosokabe to his son Morichika, before he passed away in May that year. Morichika’s accession was far from smooth; he was unpopular amongst some of the Chosokabe’s retainers (apparently due to his arrogance and short temper), and the Toyotomi, de facto masters of Japan, didn’t recognise him as the new head of the clan.

An early 20th century depiction of Chosokabe Morichika.

Morichika would try to make good on his appointment by joining the Western Army (the pro-Toyotomi side) at the Battle of Sekigahara in 1600. This would prove to be an unwise choice in the end, as the Western Army was defeated by the Eastern Army under Tokugawa Ieyasu. Although the Chosokabe had not actually been involved in the final battle, they had chosen a side and would not escape the consequences.

Morichika was punished by having Tosa taken from him. Though there would be some protest, the decision proved to be final, and the Chosokabe’s time as feudal lords was over. Motochika would campaign to have his territory restored until around 1605. In 1610, he supposedly became a monk, and although his movements around this time are unclear, by 1612, he was under direct surveillance from the new Tokugawa Shogunate.

The new Shogun was right to suspect him, as, during the Osaka Campaign in 1615, he sided with the Toyotomi, hoping to secure the restoration of Chosokabe lands in Tosa. In the event, the Tokugawa would be victorious in that campaign, snuffing out the last of the Toyotomi Clan, and securing their rule.

A contemporary kawaraban, a kind of early newspaper, depicting the fall of Osaka Castle.

Morichika is reported to have fought bravely, leading an attack on the Tokugawa’s main camp that was ultimately unsuccessful, but which managed to inflict serious casualties on the Tokugawa army before being forced to withdraw. With Osaka Castle eventually falling to the Tokugawa, Morichika initially fled, but he was discovered and then humiliated by being paraded around Kyoto before being beheaded.

Morichika’s death brought an end to the Chosokabe. Some sources state he had as many as five sons, all of whom died premature and violent deaths. Some other sources, however, suggest that he had just two children, a girl and a boy, one who married a local retainer, and the other who was whisked away after the Siege of Osaka and raised elsewhere. Unfortunately, in both cases, reliable sources are hard to come by, and the truth appears to be that the Chosokabe died with Morichika.

The Chosokabe name would be revived in later years by descendants of Motochika’s brother, Chikafusa, who had been adopted into the Shima Clan years earlier and thus survived the end of the Chosokabe. The family survived in this form until March 2025, when the last head of the family, Chosokabe Tomochika, passed away childless, aged 82.

「今は個人の時代。家を背負う時代ではありません。逆にこれからの世代が、自分の思いで新しい歴史を作っていくのも立派なことじゃないかと思いますね」

“We are now in the age of the individual. It is no longer the age to shoulder the burden of a family. On the contrary, I think it is admirable for future generations to create a new history based on their own ideas.” – Chosokabe Tomochika

Sources
https://ja.wikipedia.org/wiki/%E9%95%B7%E5%AE%97%E6%88%91%E9%83%A8%E7%9B%9B%E8%A6%AA
https://ja.wikipedia.org/wiki/%E5%85%AD%E6%9D%A1%E6%B2%B3%E5%8E%9F
https://ja.wikipedia.org/wiki/%E9%95%B7%E5%AE%97%E6%88%91%E9%83%A8%E5%85%83%E8%A6%AA
https://en.wikipedia.org/wiki/Ch%C5%8Dsokabe_Morichika
https://ja.wikipedia.org/wiki/%E3%82%B5%E3%83%B3%EF%BC%9D%E3%83%95%E3%82%A7%E3%83%AA%E3%83%9A%E5%8F%B7%E4%BA%8B%E4%BB%B6
https://ja.wikipedia.org/wiki/%E4%B8%8B%E7%94%B0%E5%9F%8E_(%E4%BC%8A%E8%B1%86%E5%9B%BD)
https://en.wikipedia.org/wiki/San_Felipe_incident_(1596)
https://ja.wikipedia.org/wiki/%E9%95%B7%E5%AE%97%E6%88%91%E9%83%A8%E6%B0%8F
https://ja.wikipedia.org/wiki/%E9%95%B7%E5%AE%97%E6%88%91%E9%83%A8%E5%8F%8B%E8%A6%AA
https://croissant-online.jp/life/54209/

November 27, 2025
Lords of the Four Provinces

You probably already know that Japan is made up of four main islands, Honshu, Kyushu, Hokkaido, and Shikoku. Most of the history we have looked at so far took place on Honshu, the main island, and we’ve mentioned Kyushu in passing once or twice. In the pre-modern era, Hokkaido was barely considered to be part of Japan at all, which leaves the smallest of the four main islands, Shikoku, a name which means ‘Four Provinces,’ so named, because it has, wait for it, four provinces!

Shikoku.
_{^{By TUBS – This vector image includes elements that have been taken or adapted from this file:, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=16385942}}

Shikoku itself had rarely been at the centre of events in the centuries before the Sengoku Jidai, but that doesn’t mean it wasn’t occasionally the site of some significant events. In the 12th century, the Taira Clan would flee to Shikoku with the Emperor Antoku, shortly before the fateful Battle of Dan-no-Ura.

During Ashikaga Shogunate rule, the island was split between the Hosokawa and Kono Clans, and the Hosokawa would have a clan under them who would go on to play a major role in the history of Shikoku, the Chosokabe.

The Chosokabe were a relatively minor clan until the mid-1400s, when Hosokawa Masamoto launched a coup which left him in effective control of the government in Kyoto. This was important for the Chosokabe because Masamoto was the nominal shugo of Tosa Province, where the Chosokabe were based. The head of the clan, Kanetsugu, was appointed Masatomo’s deputy, and since his master was practically never away from Kyoto, Kanetsugu was allowed to run things as he saw fit.

Tosa Province.
_{^{By Ash_Crow – Own work, based on Image:Provinces of Japan.svg, CC BY 2.5, https://commons.wikimedia.org/w/index.php?curid=1691856}}

Kanetsugu seems to have been a fairly capable administrator, but an ongoing war with several local clans and an increasingly arrogant attitude due to the backing he received from Masatomo made Kanetsugu increasingly unpopular, and when his patron was assassinated in 1507, the now unprotected Kanetsugu was surrounded by vengeful enemies, and the Chosokabe were all but wiped out by 1509. Whether or not Kanetsugu survived the fall of his clan is a matter of some debate; the traditional view is that he either died in battle or else took his own life, but more modern research suggests he may have survived until at least 1512, when the leadership of the clan was handed over to his son, Kunichika.

Kunichika certainly survived the fall of the clan and sought refuge with the nearby Ichijo Clan, where he would be protected until he came of age, and in 1518, he was able to reclaim his family’s castle at Okoto. Despite this restoration, however, the Chosokabe would remain a fairly minor clan, and it became Kunichika’s life’s work to not just hold onto what his clan had, but expand it.

The site of Okoto Castle, home of the Chosokabe, as it appears today.
_{^{Reggaeman – 投稿者自身による著作物, CC 表示-継承 3.0, https://commons.wikimedia.org/w/index.php?curid=6986404による}}

Between 1518 and 1560, Kunichika led the Chosokabe from being a clan that struggled to retain control of a solitary fortress to being the leading power in Tosa Province. During more than 40 years of struggle, Kunichika subjugated his neighbours and engaged in a long-term war with the Motoyama Clan, who would prove to be the only other clan that could match the Chosokabe for strength and tenacity.

At the Battle of Nagahama in May 1560, a Motoyama force of some 2000 men faced off against a Chosokabe army that was half its size. Despite this, Kunichika won a decisive victory, seriously weakening the Motoyama considerably. Unfortunately for Kunichika, he fell ill and died shortly after this victory, and was unable to completely destroy the Motoyama.

Despite the sudden death of their lord, the Chosokabe were now in a strong position, and Kunichika’s son, Motochika, stepped into his father’s shoes, continuing the war against the Motoyama and driving them back to their fortress at Asakura by late summer 1562. Though an attack on the fortress would fail, Chosokabe’s control of the surrounding countryside meant that the Motoyama began shedding vassals, who were quick to bow to the new power in the region.

Chosokabe Motochika.

In early 1563, the lord of the Motoyama, Shigetatsu, fled Asakura for Motoyama Castle, from which he launched a counterattack against the Chosokabe. The attack failed, and Shigetatsu retreated again, this time to his clan’s last bolt hole at Uryuno Castle, intending to fight to the death. Shigetatsu was denied his wish when he died of illness not long afterwards, and although his son continued the fight, the Motoyama were finally forced to surrender in 1568, after which Tosa was more or less pacified.

Meanwhile, an attack launched by the Mori Clan in 1567 had seriously weakened the Ichijo Clan, who were still nominal overlords of the Chosokabe. Taking advantage, Motochika launched a campaign that crushed other Ichijo vassals still residing in Tosa, and in 1574 he intervened in an outbreak of civil war within the Ichijo clan (rival claimants to the leadership, unsurprisingly) and established control of the whole of Tosa, which was confirmed in 1575, when an attempt by the Ichijo to recover their position was decisively defeated. The first of the four provinces of Shikoku was now his.

With Tosa, and by extension, southern Shikoku now secured, Motochika formed an alliance with Oda Nobunaga, who had already begun his own path to unifying the realm in the area around Kyoto. In the 1570s, the Chosokabe and Oda had a mutual enemy in the Miyoshi Clan, who controlled a large territory that included the lands to the west of Kyoto, Osaka Bay, and the two provinces in the east of Shikoku, Awa, and Sanuki.

The situation in 1570. The Chosokabe are in green on Shikoku, the Miyoshi are in grey, and Nobunaga’s territory is in red.
_{^{By Alvin Lee – Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=39200928}}

The Miyoshi had once been a pre-eminent power in the region, but had been in a long decline, which both clans did much to accelerate. In 1576, Motochika launched an invasion of both provinces, and although his initial efforts were repulsed, a second effort in 1577 was more successful, and by 1580, a combination of diplomacy, defection, and brute force saw the Chosokabe in effective control of both Awa and Sanuki Provinces.

The situation in 1575, showing Nobunaga’s success against the Miyoshi, who still held lands on Shikoku.
_{^{By Alvin Lee – Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=39198356}}

At the same time, diplomatic and military efforts in Iyo, the last of the four provinces, saw large parts of it come under Chosokabe control. However, intervention and support from the Mori Clan across the Inland Sea meant that Chosokabe’s control of Iyo was tenuous, and the pacification campaign dragged on for far longer than the rest of the island.

As 1580 went on, the strategic situation in the rest of the realm had shifted against the interests of the Chosokabe. The alliance with Oda Nobunaga had always been one of convenience, with Nobunaga happy to see Motochika crushing the Miyoshi, but when it became clear that the Chosokabe were going to extend their control over the whole of Shikoku, Nobunaga changed his mind.

In late 1580, he sent a demand that Motochika give up three of the four provinces and limit Chosokabe’s control to Tosa Province. Motochika refused, and in response, Nobunaga began funnelling resources to those clans on Shikoku who were still opposing the Chosokabe. Throughout 1581, tensions continued to grow, and it became obvious that Nobunaga was going to invade.

The situation in 1582, just before Nobunaga’s death. The Miyoshi are gone, though the red on the eastern end of Shikoku represents clans supported by Nobunaga, rather than territory he directly controlled. His death in June 1582 would bring an end to his ambitions on the island.
_{^{By Alvin Lee – Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=39198356}}

Fate intervened, however, when Nobunaga was betrayed and killed at the Honnoji Incident in June 1582, and in the chaos that followed, the forces assigned to the invasion were needed elsewhere, and for now, at least, the Chosokabe were safe.

Safe, but not idle, however, Nobunaga’s death meant that his support for rival factions on Shikoku came to an end, and Motochika was able to launch a concerted campaign into Awa Province, in south-east Shikoku, bringing it completely under his control and removing the last of Nobunaga’s supporters.

The immediate aftermath of Nobunaga’s death was a time of chaos on the mainland, and Motochika took advantage of this to extend his control of Shikoku even further. The most prominent of Nobunaga’s successors was Hashiba Hideyoshi, and he made arrangements with several remaining clans opposed to the Chosokabe. Though attacks were launched against the Chosokabe-held castles in Sanuki Province, they were defeated, and for a time, at least, Hideyoshi was too distracted by events elsewhere to do anything about it.

1584, the Chosokabe now control the whole of Shikoku, and the red represents territory controlled by Hashiba Hideyoshi. The Chosokabe were at the height of their power, but it wouldn’t last.
_{^{By Alvin Lee – Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=39198356}}

That would change after 1584, but we’ll talk about that next time.

Sources
https://en.wikipedia.org/wiki/Ch%C5%8Dsokabe_Motochika
https://ja.wikipedia.org/wiki/%E9%95%B7%E5%AE%97%E6%88%91%E9%83%A8%E5%85%83%E8%A6%AA
https://en.wikipedia.org/wiki/Awa_Province_(Tokushima)
https://en.wikipedia.org/wiki/Ch%C5%8Dsokabe_Kunichika
https://ja.wikipedia.org/wiki/%E5%AE%89%E5%BE%B3%E5%A4%A9%E7%9A%87
https://ja.wikipedia.org/wiki/%E9%95%B7%E5%AE%97%E6%88%91%E9%83%A8%E5%85%BC%E5%BA%8F
https://ja.wikipedia.org/wiki/%E9%95%B7%E5%AE%97%E6%88%91%E9%83%A8%E6%B0%8F
https://ja.wikipedia.org/wiki/%E9%95%B7%E5%AE%97%E6%88%91%E9%83%A8%E5%9B%BD%E8%A6%AA
https://ja.wikipedia.org/wiki/%E9%95%B7%E6%B5%9C%E3%81%AE%E6%88%A6%E3%81%84
https://ja.wikipedia.org/wiki/%E6%9C%AC%E5%B1%B1%E5%9F%8E_(%E5%9C%9F%E4%BD%90%E5%9B%BD)
https://ja.wikipedia.org/wiki/%E5%9B%9B%E5%9B%BD
https://en.wikipedia.org/wiki/Shikoku
https://en.wikipedia.org/wiki/List_of_daimy%C5%8Ds_from_the_Sengoku_period

November 25, 2025
Memento Mori, Part 3

Last time, we looked at how the relationship between Mori Terumoto and Oda Nobunaga broke down, leaving both sides on the verge of conflict. After Terumoto declared for the Shogun, Ashikaga Yoshiaki (the last Ashikaga Shogun) declared that Terumoto would serve as ‘Vice Shogun’, a slightly ambiguous position which was rendered largely moot in practice, as the Shogun relied almost entirely on Mori’s strength of arms, reducing him to little more than a figurehead.

Ashikaga Yoshiaki, the last of the Ashikaga Shoguns, and little more than a figurehead.

The first action of this new ‘Shogunate’ (read: Mori) army was supporting the besieged warrior monks of Ishiyama Hongan-ji. You may recall in the post about the Ikko-Ikki, we mentioned Nobunaga’s campaigns against Hongan-ji, which ultimately lasted more than a decade, and left the temple a charred ruin.

The Mori, possessing one of the most powerful navies amongst the Sengoku Daimyo, dispatched a fleet which made short work of the Oda forces in Osaka Bay, opening the way for supplies to be delivered to Hongan-ji. This victory prolonged the siege and gave the Mori unchallenged control of the Seto Inland Sea in the short term.

Later that year, Nobunaga sought to restore the Amago Clan (long-time enemies of the Mori) to a position of strength, putting up Amago Katsuhisa, the last Amago ‘lord’ at Kozuki Castle, in Harima Province, hoping to attract Amago loyalists and any other opponents of the Mori, and make life difficult for Terumoto.

A later image of Amago Katsuhisa, the last ‘lord’ of the Amago Clan.

In response, Terumoto himself led an army to lay siege to Kozuki, and when a relief force, led by Hashiba (later Toyotomi) Hideyoshi, arrived, Terumoto handily defeated it, driving the Oda out of Harima Province, taking Kozuki Castle, and obliging the remaining Amago partisans to commit seppuku, which isn’t bad for a day’s work.

Not long after this success, Terumoto would expand his influence in Harima still further, convincing several lords to defect to the Mori, and bottling up Nobunaga’s remaining loyalists in the province. After this series of successes, Terumoto had Nobunaga on the back foot, and in response, he pressured the Imperial Court to issue an order that Hongan-ji make peace with Nobunaga. The monks of Hongan-ji expressed a desire to make peace, but not without Terumoto, to whom they owed a debt of gratitude. In response, Nobunaga agreed and began negotiations with Hongan-ji and the Mori.

The strategic situation shifted considerably in the early winter, however, as a Mori fleet dispatched to deliver further supplies to Hongan-ji was defeated by new ironclad ships of the Oda Navy. The exact nature of these vessels isn’t clear; the word ‘ironclad’ is a direct translation from Japanese, implying the vessels were at least partially armoured, though the exact style and extent of armour isn’t clearly recorded.

An example of the type of warship used by the Mori Navy.

Shortly after this victory, which drove the Mori beyond Awaji Island and opened Osaka Bay to the Oda, Nobunaga swiftly called off negotiations and made plans to continue the war. Despite the defeat, the Mori were still in a very strong position, however, and at this point, Terumoto made plans to advance on Kyoto and take the fight to Nobunaga directly.

Plans were laid, including negotiation with Takeda Katsuyori for a simultaneous attack on Nobunaga’s ally, Tokugawa Ieyasu, and Terumoto set the date of the start of the campaign for early 1579. However, early 1579 came and went, and the Mori did not march. A series of rebellions broke out around the same time, supposedly instigated by both Nobunaga and the Otomo Clan (rivals to the Mori on Kyushu), and Terumoto had his hands full.

The situation went from bad to worse for the Mori throughout 1579, as several border clans, angered at what they saw as a ‘betrayal’ when Terumoto failed to march on Kyoto, defected to the Oda side, disrupting communications with troops on the front line, and opening several gaps in Mori defences. The Mori failure to march also resulted in no further attempts to relieve Hongan-ji, and it was forced to surrender in early 1580.

Not long after that, Nobunaga was able to focus significant forces on the Mori, and an army led by Hashiba Hideyoshi took advantage of the Mori’s weak position and launched a series of successful attacks against them, capturing castle after castle. A counter-attack in February 1582 led to a brief reprieve, but news from elsewhere was bad.

A later artistic depiction of Toyotomi Hideyoshi (then still called Hashiba) around 1582.

The Takeda, with whom the Mori had allied against Nobunaga, were decisively defeated in early Spring, and with their removal, Nobunaga turned his entire attention to the Mori. The situation was dire. A little more than five years earlier, the Mori had been a match for Nobunaga; indeed, had Terumoto marched on Kyoto, he would have had a good chance of success.

Now, however, Nobunaga was stronger than ever, and internal rebellion, defections, and military defeats meant that the Mori were far weaker in comparison. Had Nobunaga advanced, he almost certainly would have won.

As is so often the case, however, fate intervened. Nobunaga was betrayed by one of his generals in June 1582 and killed. His supporters immediately turned on each other, with Hashiba Hideyoshi, the man who had been leading the charge against the Mori, wishing to establish himself as Nobunaga’s successor, and so he concluded a swift peace with the Mori. For his part, Terumoto was glad to accept, even though it meant sacrificing three provinces. When news of Nobunaga’s death broke, Ashikaga Yoshiaki, still with the Mori, ordered Terumoto to march on Kyoto and take advantage of the situation.

A 19th century depiction of Oda Nobunaga’s final moments.

Terumoto refused, still forced to deal with internal rebellion, and although there would be plenty of opportunities to involve himself in the chaotic fighting that followed Nobunaga’s betrayal, the Mori would not move, instead adopting a ‘wait and see’ approach, which, in hindsight was wise, as although history would record Hideyoshi as the ultimate victor, in the summer of 1582, that was far from certain.

One thing that Terumoto did agree to, however, was refusing to accept the ceding of three provinces to Hideyoshi as part of their peace deal. No doubt the Mori felt that Hideyoshi had misled them (Terumoto hadn’t known about Nobunaga’s death before the agreement), and with Nobunaga’s successors tearing each other apart, the Mori were in a good position to keep hold of their territory.

Negotiations dragged on, even after Hideyoshi was able to win a decisive victory at the Battle of Shizugatake in April 1583, and he began to lose patience, threatening a resumption of war if the Mori didn’t concede. It would not be until early 1585 that a peace was actually agreed, and it was achieved largely without fresh fighting. The Mori would be allowed to keep seven provinces, representing much of the territory that had been taken by Terumoto’s grandfather, Motonari. In exchange, the Mori agreed to support Hideyoshi’s campaigns to unite the realm, especially in Shikoku and Kyushu, which the Mori assisted in invading in May 1585 and August 1586, respectively.

The strategic situation in 1584, just after Hideyoshi secured power. The Mori are represented in yellow, and Hideyoshi in red.
_{^{By Alvin Lee – Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=39198357}}

Finally, in the summer of 1586, Terumoto formally became a vassal of Hideyoshi (by now known as Toyotomi), ending decades of conflict and proving to be a significant step in bringing the Sengoku Jidai to an end more generally. A testament to the new trust placed in the Mori came in 1590, when Hideyoshi attacked the Hojo Clan, masters of the Kanto. Though the Mori did not join the campaign, Mori troops were entrusted with guarding the capital while Hideyoshi was away.

Around this time, Terumoto completed his new base at Hiroshima Castle and would take part in Hideyoshi’s ill-fated invasion of Korea in 1592. We will go into more detail about the events that followed later, but after Hideyoshi’s death in 1598, Terumoto was named as one of five regents for his infant son, Hideyori.

The five regents were meant to stabilise the realm until Hideyori came of age, but it didn’t work; Tokugawa Ieyasu was swiftly opposed by the other four as it was believed (rightly as it turned out) that he wished to overthrow the current government and make himself Shogun. The tension would eventually lead to a new outbreak of violence, and a brief campaign culminated in the decisive Battle of Sekigahara in 1600.

Teruhito and the Mori Clan were officially in opposition to the victorious Ieyasu, but had dispatched only a small force to Sekigahara, keeping their main strength at Osaka Castle to guard the heir. This was the strongest castle in the realm, and Terumoto had tens of thousands of fresh troops with which to hold it. Ieyasu, apparently aware of this, dispatched a letter to Terumoto, expressing his desire for positive relations between the two, and hoping that the Mori would depart Osaka without further violence.

The walls of Osaka Castle as they appeared in 1865.

Terumoto agreed when Ieyasu confirmed that the Mori would lose no territory in the aftermath. However, Ieyasu would almost immediately go back on his word once Terumoto was safely away from Osaka. The Mori were reduced to just two provinces in the far west, Suo and Nagato, and almost all the territory taken by Motonari and Terumoto was lost.

Terumoto himself would officially retire as head of the clan not long after Sekigahara and became a monk, though in reality, he would retain most of the actual authority within the clan. One challenge that came about almost immediately was the loss of income that came with the loss of territory. Before Sekigahara, the Mori had had an income of more than 1 million koku (a Koku being approximately how much rice one man needed for a year). After Sekigahara and the loss of five of their provinces, this income was down to less than 300,000.

This loss in income led to a loss in strength, as many of the clan’s retainers found their stipends reduced or lost entirely, leading them to seek employment elsewhere (just in case you thought Samurai were all about unquestioned loyalty.) Terumoto rather astutely recognised that this reduction might actually benefit the clan long term, as disloyal vassals would leave quickly, and even those who remained could be chosen based on ability, leading to a reduction in the clan’s overall strength, but perhaps improving skill and efficiency, at least in theory.

A 19th century photograph of Hagi Castle, where the Mori Clan were based after their forced relocation.

This would prove a wise move, as a land survey in 1610 showed that the Mori’s financial situation was better than originally assumed, and the reduction in vassals and retainers had led to a leaner, more efficient administration.

Peace in the realm would last a while under Tokugawa Ieyasu’s rule, but it was a fragile thing. In 1614, the now adult Toyotomi Hideyori (Hideyoshi’s heir) brought about a crisis when a new prayer bell was inscribed with language that was interpreted as calling for the overthrow of the Tokugawa. Hideyori holed up in Osaka Castle and called on all ‘loyal vassals’ to come to his aid. Most, including Terumoto, ignored him, and when Ieyasu marched on Osaka, he requested the Mori dispatch their navy in support, which they duly did.

Terumoto also led an army to Osaka, though the Mori would ultimately play a relatively small role in the so-called Winter Siege of Osaka. The following year, during what is called the Summer Siege, Ieyasu attacked Osaka again, this time successfully, capturing and executing Hideyori, and bringing his line to an end.

Tokugawa Ieyasu, the man who would ultimately bring the Sengoku Jidai to an end.

The Mori were again asked to dispatch an army, but delays in orders and the length of the march meant they arrived only after Osaka had fallen. There was some concern that this delay might be interpreted as treachery by Ieyasu; however, even the savvy political operator, Ieyasu, chose to lay the blame on slow communication instead, sparing the blushes of the Mori.

Terumoto, his health failing and age catching up with him, handed full control of the clan over to his heir, Hidenari, in 1621, and although a formal system of ‘dual leadership’ would continue, it was becoming increasingly clear that Terumoto’s time was running out.

He would continue to play a role in the affairs of the Mori until his death in 1625, and his clan’s distant position from the new capital in Edo afforded them a certain degree of autonomy, at least with regard to internal affairs, in the years that followed.

That would prove important in the 19th century, as the arrival of American ships in Edo Bay forced Japan to end its period of isolation. It would be the Mori Clan, based in what by then was called the Choshu Domain, who would lead the charge against the Tokugawa Shogunate, overthrowing it, and re-establishing Imperial Rule in the so-called Meiji Restoration, but we are getting way ahead of ourselves.

Mori Motonari, the last lord of Choshu Domain.

Mori Terumoto is one of the giants of the Sengoku Era. Building on the successes of his grandfather, Motonari, he led the Mori to a position in which they may well have been able to take power for themselves, had things gone a little differently. Ultimately, despite never gaining ultimate power for themselves, Terumoto and his successors would prove to be one of the success stories of this period, surviving the turmoil and even thriving in the new Japan of the 19th Century.

Sources
https://ja.wikipedia.org/wiki/%E6%AF%9B%E5%88%A9%E8%BC%9D%E5%85%83
https://ja.wikipedia.org/wiki/%E5%BA%83%E5%B3%B6%E5%9F%8E
https://ja.wikipedia.org/wiki/%E4%BA%AC%E8%8A%B8%E5%92%8C%E7%9D%A6
https://ja.wikipedia.org/wiki/%E9%B3%A5%E5%8F%96%E5%9F%8E
https://ja.wikipedia.org/wiki/%E9%89%84%E7%94%B2%E8%88%B9
https://ja.wikipedia.org/wiki/%E5%89%AF%E5%B0%86%E8%BB%8D
https://en.wikipedia.org/wiki/M%C5%8Dri_Terumoto
https://ja.wikipedia.org/wiki/%E5%B0%BC%E5%AD%90%E5%8B%9D%E4%B9%85
https://en.wikipedia.org/wiki/Toyotomi_Hideyoshi
https://en.wikipedia.org/wiki/Tokugawa_Ieyasu

November 20, 2025
Memento Mori, Part 2

Last time we looked at Mori Motonari, the lord who took his clan from struggling to hold onto their domains to controlling one of the largest territories of any clan during the Sengoku Period. Motonari’s son, Takamoto, died early, and so it would fall to his grandson, Terumoto, to lead the clan after Motonari himself passed in 1571.

Mori Terumoto

Terumoto was born in 1553, at a time when his clan, the Mori, were already on the rise. Under the leadership of Motonari, the clan had recently purged the Inoue, who had presented a serious internal threat, obliging Motonari to get rid of them. Shortly before Terumoto was born, the Ouchi, nominal overlords of the Mori, were seriously weakened by an internal coup, allowing Motonari to expand his clan’s power base still further, and not long after that, the Mori would win the decisive Battle of Itsukushima, establishing themselves as the (relatively) unchallenged power in the region.

Throughout his early life, Terumoto hardly saw his father or grandfather, as both men were frequently on campaign, and the young boy, as the future leader of the Mori, was kept safe, far from the fighting. Takamoto was, by this point, technically the leader of the Mori (though Motonari would remain in control), and when he died suddenly in 1563, Terumoto, just 11 years old, became the nominal head of the clan. Due to his youth, however, Motonari agreed to serve as ‘co-leader’, whilst (again) retaining all the actual power.

In 1565, as a sign of how far the Mori had risen, Terumoto’s coming-of-age ceremony was attended by an official representative of the Shogunate, lending formal (if only symbolic) prestige to the young man. After this, Terumoto, who was now legally an adult, became the official head of the clan, and from then on, most legal documents carried his signature, though he would continue to defer to his grandfather in practice.

Later that year, Terumoto would join his grandfather in Izumo Province, taking part in the campaign against the Amago, who had once been strong enough to demand fealty from the Mori, but were now on their last legs. This final campaign against the Amago would be concluded successfully in late 1566, with the surrender of their last stronghold at Gassan-Toda Castle, signalling the end of the war and the Amago Clan.

The site of Gassan-Toda Castle as it appears today.
_{^{安来市政策秘書課 – 投稿者自身による著作物, CC 表示-継承 4.0, https://commons.wikimedia.org/w/index.php?curid=74692475による}}

Despite this victory, an uprising of former Amago retainers would occur in June 1569, followed by a similar uprising amongst former Ouchi warriors in October. These twin uprisings were either instigated or supported after the fact by the Otomo, whom the Mori had been fighting for control of Northern Kyushu with.

Mori control of Izumo, Suo, and Nagato provinces was suddenly under serious threat. Withdrawing forces from Kyushu allowed them to quickly deal with the Amago rebellion, but the Ouchi proved a much sterner test, and required the Mori to dedicate even more resources to putting them down. Though victorious in early 1570, the consequences were that the Mori lost all their influence in Kyushu and had to continue a long, bloody campaign, trying to stamp out the embers of the Amago.

Suo Province

Izumo Province

Nagato Province

_{^{By Ash_Crow – Own work, based on Image:Provinces of Japan.svg, CC BY 2.5, https://commons.wikimedia.org/w/index.php?curid=1691776}}

Around this time, wider events began to have an impact on the Mori as well, bringing them onto the main stage of events in and around Kyoto. Earlier, in 1565, Shogun Ashikaga Yoshiteru was assassinated in what became called the Eiroku Incident, and his replacement, Ashikaga Yoshiaki, went looking for support from the clans further away from the capital.

In 1568, the new Shogun dispatched a request for aid to several powerful leaders, including Uesugi Kenshin, Oda Nobunaga, and Mori Motonari. The Uesugi and Mori refused, but Nobunaga, based closer to the capital and possessing uncommon ability and ambition, responded positively and dispatched forces to Kyoto.

Ashikaga Yoshiaki, the last of the troubled Ashikaga Shoguns.

Not long after that, the Oda and Mori began to cooperate against their common enemy, the Miyoshi (who also happened to be the clan behind the assassination of the previous Shogun, which was handy). Over the next few years, an alliance would be established, and Nobunaga would actually dispatch forces to help the Mori put down the Amago and Ouchi, but beyond that, there would be little direct cooperation.

When Mori Motonari died in 1572, leaving Terumoto to lead the clan alone, relations with Nobunaga were already in decline. Previously, the Mori had sought to use the authority of the Shogun (by now under Nobunaga’s control) to advance their own goals, and for a time, Nobunaga was happy to acquiesce, but after 1572, it became clear that Nobunaga had plans of his own that didn’t necessarily involve the Mori.

Though the Shogun had largely been under Nobunaga’s control since 1565, at first, it had been a subtle arrangement. Nobunaga was in charge, but Yoshiaki was permitted to still act like the Shogun, even if his commands and proclamations (such as they were) were increasingly screened and eventually written by Nobunaga.

Oda Nobunaga.

Yoshiaki didn’t passively accept this, however. His problem was that he had little military strength of his own (a problem for the Ashikaga Shoguns since the very start), and with Nobunaga’s pre-eminent military position, the Shogun needed help. He thought he might find it in the Mori, one of the few clans that had the strength to challenge Nobunaga directly.

In 1573, at the recommendation of the Shogun, Terumoto was granted the title of Uma no Kami, which translates as “Master of Horse”. Though Imperial titles had long since become little more than baubles, they still carried prestige, and Yoshiaki almost certainly did it to butter the Mori up and bring them over to his side, against Nobunaga.

Yoshiaki was desperate by this point. Earlier that year, Takeda Shingen, who had agreed to march on Kyoto at least nominally in support of the Shogun, had died suddenly, bringing an end to the prospect of Takeda support. In early Spring, Yoshiaki raised an army anyway, hoping to take advantage of Nobunaga being distracted elsewhere, but instead suffered a series of defeats, which culminated in the Battle of Makishima Castle in July, which saw Yoshiaki exiled from Kyoto.

The monument at the ruins of Makishima Castle.
_{^{Muscla3pin – 投稿者自身による著作物, CC 表示-継承 4.0, https://commons.wikimedia.org/w/index.php?curid=77200674による}}

Shortly after this, Nobunaga, aware of his vulnerable position, wrote to Terumoto, assuring him that it was the actions of the Shogun that led to Oda troops formally occupying the capital, and that he would do everything he could to maintain peace in the realm. Given that there hadn’t been peace in the realm for more than a century at this point, it leads us to conclude Nobunaga was just being polite.

Though Terumoto probably eyed Nobunaga’s expansionism warily, the alliance was, for now, convenient for both sides, as it largely secured the border between the two powerful clans and allowed them to carve up the territory of the smaller clans caught in the middle. Terumoto did continue to try to mediate a peace between Yoshiaki and Nobunaga, though neither side seems to have negotiated with much faith.

Scholars speculate that both Terumoto and Nobunaga wanted to avoid a situation in which the Shogun would flee to Mori territory, Terumoto because had no interest in helping Yoshiaki, but couldn’t rely on some of his more tenuous vassals not making trouble, and Nobunaga for pretty much the same reason, the Mori were one of the few clans strong enough to oppose him, and if they backed the Shogun, Nobunaga might be in trouble.

Though Nobunaga was allied with the Mori, he took other actions that would be considered unfriendly. On the Eastern borders of Mori territory (the West, as far as Nobunaga was concerned) lay the Urakami Clan, who dominated the three provinces of Bizen, Harima, and Mimasaka. The Mori and Urakami had engaged in a long war before the Urakami had agreed to submit to the Mori in exchange for recognition of this territory, terms to which the Mori agreed, effectively turning the Urakami into vassals.

Bizen Province

Harima Province

Mimasaka Province

However, Nobunaga issued a “Red Seal Letter” (an official, legally binding document named for its eponymous red seal), recognising the Urakami as lords of the three provinces. This was, in effect, simply making official something that was already a fact; however, when the Urakami accepted the letter, they effectively ceased to be Terumoto’s vassals, that is, if the Mori accepted the new situation.

The Mori, not surprisingly, did not. In 1575, they attacked the Urakami, defeating them in a series of battles and essentially eliminating them as a power, taking direct control of the provinces. The Urakami had apparently expected Nobunaga to dispatch forces to aid them, but he had erred on the side of caution, deciding that the Urakami were an acceptable sacrifice for keeping the peace with the Mori, at least for now.

An immediate consequence of this was that there were no more buffers between the Mori and Oda territories, which now shared a border. The relationship was already tense, and it only grew worse as both sides became involved in Tajima Province. Expecting that Nobunaga would seek to make the province part of his domain, Terumoto made an alliance with the province’s local power, the Yamana. You may remember that name from earlier posts, and well done if you did; the Yamana were still around at this point, though no longer the great clan they once were.

A map showing the borders between the Mori (in Yellow) and the Oda (in Red) in 1575, with Tajima Province marked.
_{^{By Alvin Lee – Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=39200929}}

Then in 1576, the Shogun, Ashikaga Yoshiaki, having been forced to flee Kyoto by Nobunaga, found himself in Bingo Province, controlled by the Mori. Terumoto was not happy about this. Although he had ostensibly supported the restoration of the Shogunate, he understood that the only way that could happen was through war with Nobunaga, which he had no interest in. When the Shogun showed up on his doorstep and formally asked the Mori to support him in returning to Kyoto, then Terumoto was in a tricky spot.

The Mori had promised Nobunaga that they would not harbour the exiled Shogun. On the other hand, Nobunaga had taken actions that were widely seen as trying to undermine Mori power, and although he had attacked them directly, the damage had been done.

Terumoto, for his part, took a long time making up his mind. We’ll never know exactly what he was thinking, but it’s easy to imagine that Terumoto had plenty of reason to be wary of Nobunaga, who had already meddled in Mori affairs and would probably do so again if given the chance. The Mori were also one of the few clans with the power to actually face Nobunaga directly, something that Terumoto must have been aware of.

Terumoto would declare for the Shogun in May 1576, effectively ending his alliance with Nobunaga and setting the Mori on a collision course with the Oda, but more on that next time.

Sources
https://ja.wikipedia.org/wiki/%E6%AF%9B%E5%88%A9%E8%BC%9D%E5%85%83
https://en.wikipedia.org/wiki/M%C5%8Dri_Terumoto
https://ja.wikipedia.org/wiki/%E6%9C%88%E5%B1%B1%E5%AF%8C%E7%94%B0%E5%9F%8E
https://ja.wikipedia.org/wiki/%E6%A7%87%E5%B3%B6%E5%9F%8E%E3%81%AE%E6%88%A6%E3%81%84
https://ja.wikipedia.org/wiki/%E6%9C%B1%E5%8D%B0%E7%8A%B6
https://en.wikipedia.org/wiki/Oda_Nobunaga
https://en.wikipedia.org/wiki/Ashikaga_Yoshiaki

November 18, 2025
Memento Mori, Part 1.

If you’ve been reading my blog for a while, you might be forgiven for thinking that Japanese history was mostly focused on the Kanto or Kansai regions (modern Tokyo and Kyoto/Osaka, respectively). Whilst the capital was in Kyoto, and some of the most powerful clans were based either there or in the Kanto, there were others, just as powerful and just as ambitious, who were based in other parts of Japan.

One such clan was the Mori, who we have mentioned briefly previously but are deserving of a much closer look. The subject of this post is Mori Motonari, and though he would go on to establish himself and his clan as one of Japan’s strongest, when he was born in 1497, there was little to indicate that the Mori would be anything other than a regional footnote.

Mori Motonari, our subject for today.

In the early 15th century, the most powerful clan in the region was the Ouchi, who played a significant role in the turmoil surrounding Kyoto and the Ashikaga Shogunate in the late 1400s. The Mori were based in Aki Province, in modern-day Hiroshima Prefecture, and found themselves caught up in the conflict between the Ouchi and the Hosokawa, who by this point were in effective control of the Shogunate.

In 1500, in a bid to avoid having to choose sides, Motonari’s father, Hiromoto, retired as head of the clan and was replaced by his son (Motonari’s older brother), Okimoto. Motonari would have a tough childhood, even by the standards of the day. His mother died in 1501, and his father in 1506, either from stress or alcohol poisoning (or a combination of the two).

In 1507, Okimoto had chosen his side, as he accompanied the Ouchi to Kyoto, leaving 10-year-old Motonari back in Aki. The young lad then had his income embezzled by unscrupulous vassals, leaving him destitute. However, the embezzler died suddenly in 1511, and Motonari’s income was restored.

Also in 1511, Okimoto returned from Kyoto and set about preserving the clan’s position in Aki Province. In 1513, Motonari would make a formal pledge of loyalty to his brother, supporting Okimoto’s rule, and (ideally) avoiding the kind of fratricidal violence that plagued so many of Japan’s other clans.

Aki Province.
_{^{By Ash_Crow – Own work, based on Image:Provinces of Japan.svg, CC BY 2.5, https://commons.wikimedia.org/w/index.php?curid=1645417}}

In 1515, there was an outbreak of violence in Aki and neighbouring Bingo (yes, it was really called that) province. In response, the Ouchi dispatched a member of the Takeda Clan to restore order. (You may remember we spoke previously of several branches of the Takeda family, this one is sometimes called the Aki-Takeda, due to the location of their base.)

The Aki-Takeda proved to be unreliable vassals, however, as they took advantage of the chaos to rebel against the Ouchi and take control of several castles for themselves. Okimoto, continuing his service to the Ouchi, would attack the Aki-Takeda and take one of their castles, forcing them to withdraw and giving birth to a local rivalry that would be important for Motonari and the Mori Clan.

In 1516, Okimoto died suddenly, aged just 24, apparently also from alcohol poisoning. His son was just two years old, and so Motonari would become the guardian and acting head of the clan. A sudden change in leadership can leave a clan vulnerable, and the Aki-Takeda sought to take advantage, attacking several castles in Aki Province that protected the Mori heartlands.

Mori Okimoto, Motonari’s brother. His sudden death paved the way for Motonari’s rise to power, though it would be said he deeply mourned his brother’s passing.

Motonari was obliged to respond and proved his mettle several times in the war that followed. Between 1517 and 1522, Motonari would engage in a series of sieges and battles against the Aki-Takeda, which would see Mori gradually extend control across southern Aki province (in the area around modern Hiroshima), and even into neighbouring Bingo.

Despite his personal successes, the overall situation remained chaotic, and in 1523, the Amago Clan, seeking to expand their influence, advanced into Aki Province. Motonari, who had fought for the Ouchi up to that point, switched sides and aided the Amago in their conquests of several castles in the region.

This relationship would be relatively short-lived, however. In 1523, Okimoto’s son (Motonari’s nephew), who had been the nominal head of the clan, died, aged just 9. As was common, there was no clear successor, and although he had been the de facto head for years, Motonari was opposed by a faction that wanted his half-brother in charge instead.

Initially, Motonari was able to secure enough political support to be named head of the clan, and he was even recognised as such by the Amago. Almost as soon as the ink was dry, though, the Watanabe Clan, who had supported Motonari’s half-brother, began agitating against him.

The situation worsened when several other clans joined the conspiracy, apparently with the approval (or possibly even direct support) of the Amago Clan. Motonari’s position was still insecure, and he was forced to take action, launching a purge of those involved. Japanese politics at this time was usually an extremely bloody affair, and it wasn’t uncommon for entire families to be wiped out as punishment for rebellion.

Though Motonari ordered the death of his half-brother and his key supporters, he stopped there. No harm was done to the wives and children of the conspirators, as Motonari himself seemed to believe the incident was not so much a rebellion as it was interference from the Amago. Indeed, it was even suggested at the time that Motonari deeply regretted the killings, blaming himself for not having been able to stop the conspiracy, and the Amago for having encouraged it.

Quite why the Amago were so keen to conspire against Motonari isn’t clear, but they’d soon have cause to regret it. In 1525, as a response to Amago meddling, Motonari switched sides again, giving his support back to the Ouchi, who had largely stabilised their own situation by this point. Motonari would use this new alliance to expand his control of Aki Province even further, as many of the local clans remained loyal to the Amago and were now prime targets for Motonari’s revenge and political ambitions.

Mori Motonari’s Battle Flag.

Over the next few years, Motonari would use a combination of diplomacy, threat, and outright force to establish broad control of Aki Province. In 1532, 32 local vassals of the clan signed a document pledging to follow Motonari’s lead and establishing him as the final arbiter in legal matters within the province. Also that year, Motonari was (with the support of the Ouchi) granted an Imperial title. As we’ve discussed previously, these titles were largely just for show by this point, but they did serve to increase Motonari’s personal prestige.

In 1540, the ongoing Amago-Ouchi war reached a new level of escalation, as the Amago marched into Aki Province with 30,000 men. Standing in their path was the Mori home castle at Yoshida-Koriyama, which quickly came under siege. Despite being outnumbered as much as 10 to 1, Motonari held out, and the Battle of Yoshida-Koriyama (which was actually a series of battles) eventually ended in the Mori’s favour, as the castled was relieved by Ouchi reinforcements, and the Amago were forced into a humilitating retreat, ending their attempts to conquer Aki, and leaving Mori control of the province in a much stronger position.

In 1545, Motonari’s wife died, and shortly after that, he announced his retirement as head of the clan. In a letter to his son, he strongly implied that it was grief over the passing of his wife that led him to make the decision. In 1546 (or possibly 1547), Motonari formally retired in favour of his son, Takamoto. However, as was common, Motonari’s ‘retirement’ was just for show, and he retained almost complete control of the clan.

As control over Aki and Bingo provinces was established, and Mori power increased, Motonari was now in a strong enough position to deal with his remaining internal enemies. In 1550, after gaining the tacit approval of the Ouchi (still the Mori’s nominal overlords), Motonari launched a violent purge of the Inoue Clan, one time vassals of the Mori, who had begun to operate independently, presenting a threat to Mori internal stability.

Bingo Province.
_{^{By Ash_Crow – Own work, based on Image:Provinces of Japan.svg, CC BY 2.5, https://commons.wikimedia.org/w/index.php?curid=1652300}}

What followed was the massacre of up to 30 individuals, which left the other Mori vassals fearing for their lives. However, Motonari gathered 238 of them and had them sign a pledge of loyalty and obedience. All agreed, and the end of the Inoue Clan further cemented Motonari’s position.

A year later, the Ouchi themselves fell victim to an internal coup, their leader was assassinated, and replaced by his son, though the real power would be with the new regent, Sue Harutaka (pronounced soo-eh, by the way). Motonari took advantage of the chaos to capture several castles that remained loyal to the old Ouchi Lord, and Harutaka agreed, recognising the Mori as lords of the Aki and Bingo provinces.

This rapprochement didn’t last long (they never do), with Harutaka soon regretting the power he had given Motonari, and he demanded that he return control. Motonari, unsurprisingly, refused, and shortly after that, conflict broke out. The problem for the Mori was one of numbers; Harutaka was regent of the Ouchi Clan, the regional power, and could muster 30,000 men, to the Mori’s 5000.

Fortunately for Motonari, the Ouchi were facing several rebellions in the aftermath of the coup, and their forces were divided. This gave the Mori their chance, and at the Battle of Oshikibata in 1554, the Mori, despite being outnumbered nearly 2 to 1, launched a surprise attack against the Ouchi and won.

A later image of Motonari at the Battle of Itsukushima.

A year later, Harutaka himself led a large army to put down the Mori, laying siege to Miyao Castle on Itsukushima (site of the famous ‘floating’ Torii gate), with 20,000 men. Unbeknownst to Harutaka, however, was that this was exactly what Motonari had hoped he’d do. The Mori had one of the most powerful navies in Japan at the time, and what followed was a combined sea and land operation, in which the outnumbered Mori launched another surprise attack, trapping the Ouchi and effectively wiping them out, with Harutaka himself amongst the dead.

The Battle of Itsukushima was not the end of the Ouchi, but they were never again a serious force. Over the next two years, the Mori would expand into the former Ouchi heartlands of Suo and Nagato provinces, as well as advancing in Iwami Province, gaining control of the valuable silver mines there.

In a sign of how far things had changed, the Amago, who had previously been able to exert control over the Mori, now found that they had to deal with them on equal terms, with the conflict over the Iwami Silver Mines ending in the Mori’s favour.

Iwami Province.
_{^{By Ash_Crow – Own work, based on Image:Provinces of Japan.svg, CC BY 2.5, https://commons.wikimedia.org/w/index.php?curid=1682513}}

In 1563, with Mori control reaching new heights, Takamoto, Motonari’s son and heir, died, leaving his son, Terumoto, as the new ‘leader’ of the Mori. The reality, of course, was that Motonari had retained control, and Terumoto was a child besides, leading to a kind of ‘dual leadership’, which was supposed to last until Terumoto came of age, but of course lasted much longer.

In 1566, Motonari, with Terumoto in tow, attacked the last Amago stronghold in Izumo province, forcing their surrender in November, and bringing a final end to the Amago, who had once been the region’s dominant power.

The next year, Terumoto was 15, and officially came of age, with Motonari announcing he would end the ‘dual leadership’. Apparently, Terumoto begged him to reconsider, and so Motonari would stay on as co-leader, though his health was already declining, and by the end of the 1560s, it was becoming clear that Motonari’s time was nearly up.

Mori Motonari would eventually pass away in June 1571, aged 75, possibly from cancer or old age. At his birth, the Mori had been a minor clan in a distant province, the proverbial leaf on the wind, buffeted to and fro depending on the whims of their powerful neighbours. As he lay dying 75 years later, Motonari ruled one of the largest territories of the era, and had established his clan as one of the truly great Sengoku Clans.

It would fall to his grandson, Terumoto, to continue this legacy, and though he would often prove equal to the task, fate was not yet done with the Mori Clan.

Mori Terumoto

Sources
https://ja.wikipedia.org/wiki/%E6%AF%9B%E5%88%A9%E5%85%83%E5%B0%B1
https://ja.wikipedia.org/wiki/%E5%8E%B3%E5%B3%B6
https://ja.wikipedia.org/wiki/%E5%8E%B3%E5%B3%B6%E3%81%AE%E6%88%A6%E3%81%84
https://ja.wikipedia.org/wiki/%E9%98%B2%E9%95%B7%E7%B5%8C%E7%95%A5
https://ja.wikipedia.org/wiki/%E6%8A%98%E6%95%B7%E7%95%91%E3%81%AE%E6%88%A6%E3%81%84
https://ja.wikipedia.org/wiki/%E5%90%89%E7%94%B0%E9%83%A1%E5%B1%B1%E5%9F%8E%E3%81%AE%E6%88%A6%E3%81%84
https://ja.wikipedia.org/wiki/%E5%90%89%E7%94%B0%E9%83%A1%E5%B1%B1%E5%9F%8E
https://ja.wikipedia.org/wiki/%E9%AB%98%E6%A9%8B%E8%88%88%E5%85%89
https://ja.wikipedia.org/wiki/%E5%A6%99%E7%8E%96
https://ja.wikipedia.org/wiki/%E5%A3%AC%E7%94%9F%E7%94%BA_(%E5%BA%83%E5%B3%B6%E7%9C%8C)
https://ja.wikipedia.org/wiki/%E4%BA%95%E4%B8%8A%E5%85%83%E7%9B%9B
https://en.wikipedia.org/wiki/Aki_Province
https://ja.wikipedia.org/wiki/%E6%AF%9B%E5%88%A9%E8%88%88%E5%85%83

November 13, 2025