Chris Perry, Author

Tag: Japanese feudal history

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
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
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