The Battle of Bitchu Takamatsu-jo Castle (備中高松城の戦い)

The Battle of Bitchu Takamatsu-jo Castle was a battle in 1582 in which, on the order of Nobunaga ODA, his karo (retainer) Hideyoshi TOYOTOMI conquered Takamatsu-jo Castle, owned by Muneharu SHIMIZU, in Bitchu Province in the territory of the Mori clan.

Hideyoshi besieged Takamatsu-jo Casle by inundation tactics, during which Mitsuhide AKECHI betrayed and killed his lord Nobunaga ODA in a rebellion at Honno-ji Temple in Kyoto City. Hideyoshi made a peace treaty with Mori, and after he confirmed the seppuku of Muneharu SHIMIZU, sent his troops back to Kyoto to beat Mitsuhide AKECHI.

Process of the Battle
Situations leading to the Battle
Bitchu Province in the Sengoku period (period of Warring States) was split among numerous kokujin ryoshu (local samurai lords) after the Hosokawa clan, shugo (provincial constable) had gone into decline, but the Mimura clan stood out among them. Although Iechika MIMURA, by approaching the Mori clan in Aki Province, who ruled the Chugoku region in place of the Amago clan in Izumo Province, expanded his territories to Bizen Province and Mimasaka Province, he was assassinated by Naoie UKITA, who was under the Urakami clan in Bizen, followed by the Mimura clan's loss at the Battle of Myozen-ji Temple and their decline. In a disturbance in the Bitchu area, the Miura clan was defeated by the Mori clan, cooperated with Naoie, after which many lords of a castle under the Mimura clan went to the Mori clan for help, one of whom was Muneharu SHIMIZU.

In the Kinai region, Nobunaga ODA successfully arrived at Kyoto, exterminated his opposing forces known as the anti-Nobunaga network, drove out shogun Yoshiaki ASHIKAGA, put the Muromachi bakufu (Japanese feudal government headed by a shogun) to an end, and carried out his task of unification of the whole country. The Mori clan and Nobunaga were on friendly terms during the times of Motonari MORI, but his successor Terumoto MORI protected Yoshiaki in the bakufu, and in addition, formed an alliance with Ishiyama Hongan-ji Temple, which was the largest of the anti-Nobunaga forces, growing more hostile toward Nobunaga. Since Nobunaga needed to drive into submission the Mori clan, who backed up Ishiyama Hongan-ji Temple, he ordered his vassal Hideyoshi HASHIBA to begin conquering Chugoku in 1578. First, Hideyoshi broke into Harima, reducing the Kodera clan, the Akamatsu clan in Okishio, and the Akamatsu clan in Tatsuno to obedience, and destroyed the opposing Akamatsu clan in Sayo, to consolidate its dominance. But the Chugoku Conquest was full of troubles, from the beginning as Murashige ARAKI in Settsu Province, who had supposedly been on Hideyoshi's side, cooperated with Ishiyama Hongan-ji Temple and the Mori clan to rise in revolt while the Kodera clan and the Bessho clan led a rebellion in Harima. Hideyoshi also lost his right-hand man, Shigeharu, or Hanbei, TAKENAKA at the Battle of Miki, which put the Bessho clan to an end, while he lost the remnant troops of the Amago clan including Katsuhisa AMAGO at the Battle of Kozuki-jo Castle. After finally conquering Harima again, Hideyoshi entered into Tajima Province and Inaba Province, and reduced Toyokuni YAMANA to obedience, beat Tsuneie KIKKAWA of the Mori clan at the Battle of Tottori-jo Castle, who was part of the anti-Oda forces led by the Yamana clan, and ordered his brother Hidenaga and Keijun MIYABE to conquer the Sanin region.

At first, Naoie UKITA acted under the dominance of the Mori clan and climbed up the ranks after driving out Munekage URAGAMI, who was his lord but was more on Oda's side, but once he found out how powerful the Oda clan and Hideyoshi were, he gave up on the Mori clan and offered to surrender to Hideyoshi. Naoie died of an illness in 1581, and was succeeded by his son Hideie UKITA, putting Bizen under the influence of Hideyoshi. As described above, the Battle of Bitchu Takamatsu-jo Castle occurred in situations where Hideyoshi, or the Oda clan, were in a superior position.

Process of the Battle

Since the areas beyond Okayama City, Bizen Province, which were governed by Hideie UKITA, were under the influence of Mori, the Oda forces and the Mori forces ended up having fierce battles around the borders between Bizen Province and Bitchu Province. On April 17, 1582, Hideyoshi at last left Himeji-jo Castle for Bitchu in his departure for the front with his 20,000 soldiers. On the way, he watched for the movement of the Ukita clan in Kameyama-jo Castle, also known as Numa-jo Castle, now Higashi Ward, Okayama City, where the Ukita clan had once resided, making sure that the Ukita clan would take sides with the Oda forces, and entered into Bitchu with 30,000-strong troops, with the addition of Ukita's 10,000 soldiers.

Bitchu Takamatsu-jo Castle was then one of the few hirajiro or numajiro (castles built on the level ground) which were based on swamps, and was suitable for firearms and cavalry operations. Chozaemon no jo Muneharu SHIMIZU, a resourceful man, was in charge of the castle with about 3,000 soldiers inside, which made it a difficult castle to conquer. Therefore, Hideyoshi adopted the tactic of conquering the small castles surrounding Bitchu Takamatsu-jo Castle one after another and then lay siege to the castle.

On May 17, the Hideyoshi forces besieged the castle with an army of as many as 30,000 troops, led by the Ukita forces. Though they attacked the castle two times, they lost in face of the counterattacks by johei (castle garrisons). Additionally, with the 40,000 support troops led by Terumoto MORI approaching, Hideyoshi dispatched a messenger to his lord Nobunaga, who had just defeated the Takeda clan in Kai Province, to send over support troops. While Nobunaga replied that he would send the troops of Mitsuhide AKECHI, who had subjugated Tanba Province, but gave strict orders to conquer Bitchu Takamatsu-jo Castle as soon as possible, Hideyoshi, alarmed and frustrated, heard his strategist Kanbei Yoshitaka KURODA offer an idea of using inundation tactics. Considered to have taken a cue from an episode in which Zhi Bo during the Chunqiu period in China conquered Jinyang Castle by inundation, the inundation tactic was a clever idea which made full use of the merits of numajiro that was a swamp.

Adopting this clever tactic, Hideyoshi immediately started building an embankment. This was a firm, long embankment that measured about four kilometers toward the southeast from Monzen Village, now around Ashimori Station of the JR West Kibi Line, to Kawazugahana, at the southern foot of Mt. Ishii, eight meters high, 24 meters deep, and 12 meters wide, designed to block the waters of Ashimori-gawa River. Masakatsu HACHISUKA was put in charge of the embankment while Tadaie UKITA, under the direction of Kanbei KURODA, was in charge of the difficult area from Monzen Village to Shimoideta Village. The Hachisuka clan was responsible for Harakosai Village, Yoshiharu HORIO, Chikamasa IKOMA, Bitchu KINOSHITA, Shigeharu KUWAYAMA, Masaharu TODA for the areas from Matsui to Honkoyama, and the people of Tajima Province for the areas beyond Kawazugahana, while Nagamasa ASANO assembled boats and sendo (boatmen) to make preparations for attacking the castle when it would be floating on a lake. Soldiers and peasants were recruited for the embankment and paid 100 mon of money and one sho of rice per bale, which was extremely high-paying for the time.

According to "Busho Kanjoki" (Collection of Samurai Generals' Letters of Appreciation for Distinguished War Services), the total cost of the embankment amounted to as much as 635,040 kanmon and 63,504 koku (crop yields). The embankment was completed in just 12 days from the start on June 8, which happened to be in the rainy season, and the long-lasting rain swelled the Ashimori-gawa River, developing a lake of 200 ha. This rendered Takamatsu-jo Castle a solitary island. After the completion of the embankment, Hideyoshi placed guards on it over the castle.

At the same time, as the unpredictable inundation tactics stirred the castle, the declining provisions of rice for the army by losing their supply lines, and the fact of not having support troops from the Mori clan including Takakage KOBAYAKAWA and Motoharu KIKKAWA combined to wear down the morale of the troops. As Mori's support troops were unable to move on in face of the lake built by Hideyoshi, and finding that Nobunaga's support troops were coming, they decided to make peace with Hideyoshi.

Mori sent Ekei ANKOKUJI, a military monk, for Kanbei KURODA to offer peace negotiations under the conditions of 'the cession of the five countries and the security of the troops in the castle.'
But Hideyoshi declined it and demanded 'the cession of the five countries and the seppuku of Muneharu SHIMIZU,' which failed to produce an agreement. Mori told Muneharu SHIMIZU that they were unable to rescue him and that he should surrender to Hideyoshi, but Muneharu refused to accept it, saying he would share his fate with the castle.

Mori attempted to convince Muneharu by sending Ekei ANKOKUJI over into Takamatsu-jo Castle, but Muneharu said he was not afraid to lose his life as long as he could save the Mori clan, his master, and the lives of his troops, leaving a petition to Ekei ANKOKUJI, which was to save the lives of the besieged in exchange for the lives of the four people: his brother Seigetsu, his vassals Denbe NANBA and Saemon SUECHIKA, and himself.

At just about the same time, on the evening of July 2, Hideyoshi captured the messenger sent by Mitsuhide AKECHI to Mori, got a secret letter saying that Nobunaga had lost his life by the rebellion of Mitsuhide AKECHI at Honno-ji Temple in Kyoto City. Hideyoshi promptly took counsel with Kanbei KURODA, establishing a policy of making peace with Mori as soon as possible and of going to Kyoto to subjugate Mitsuhide AKECHI.

Hideyoshi held a thorough cover-up of the fact that Nobunaga had died, trying not to let the Mori clan know that Hedeyoshi had no backing after Nobunaga's death. On the following day, 3 July, Hideyoshi called Ekei ANKOKUJI, divided the land between Kawabe-gawa River, or Takahashi-gawa River, and Yahata-gawa River, and proposed the jijin (suicide by the sword) of Muneharu SHIMIZU as a condition for reconciliation. The Mori clan had no choice but to accept the proposal, completing their reconciliation.

Muneharu SHIMIZU held a parting feast with the sake and sakana (appetizers taken with alcoholic drinks) given by Hideyoshi, ordered his vassals to clean up the castle grounds, and dressed himself up. Subsequently, Muneharu and three others boarded the boat sent by Hideyoshi, rowed to his headquarters, and had a drink together. After performing a dance, Muneharu killed himself with a death haiku, which read: Now is the time to go beyond this life, leaving a samurai's name as long lasting as moss on a pine tree. The other three followed him in sequence.

Hideyoshi praised Muneharu as a model for samurai, and by July 5, he left Ietsugu SUGIHARA in Takamatsu-jo Castle and headed east on Sanyodo Road, which is known as Chugoku Ogaeshi (the term refers to the reaction to the Honno-ji Incident by Hideyoshi HASHIBA, in which he rushed back to Bitchu even though he was in a battle with Mitsuhide AKECHI in Yamazaki which is near the boundary between Settsu Province and Yamashiro Province when he learned of the news).

Situations after the Battle
By defeating Mitsuhide at the Battle of Yamazaki on July 12, Hideyoshi practically became Nobunaga's successor. Well aware of how powerful Hideyoshi was, the Mori clan kept peace with him and assisted in his struggle for supremacy. Later in the Toyotomi government, Terumoto and Takakage became members of its Gotairo (Council of Five Elders).

After its fall, Butchu Takamatsu-jo Castle became home to the Hanabusa clan, a karo of the Ukita clan. Since the Hanabusa clan acted against its lord and joined the East squad at the Battle of Sekigahara, they were promoted to hatamoto (direct retainer of the bakufu) in the Edo period. After holding jinya (regional government office) in Bitchu Takamatsu-jo Castle for several years, they moved to Azo, Bitchu Province, now Azo, Soja City, leaving the castle deserted.