Siege of Miki

三木合戦

Oda Clan

Harima Province

Bessho Clan

Date:  3/29 of Tenshō 6 (1578) to 1/17 of Tenshō 8 (1580)

Location:  Miki Castle in Harima Province

Synopsis:  Harima Province served as a buffer zone between the Mōri and Oda clans.  To protect their own interests, local clans, including kokujin such as the Bessho, sought to navigate between these two spheres of influence by aligning with one or both clans.  Owing to a deterioration in relations with the Oda, Bessho Nagaharu abandoned them in favor of the Mōri and then holed-up in Miki Castle to face the consequences of betraying the Oda.  Hashiba Hideyoshi commanded forces on the ground to capture auxiliary sites and cut supply lines to Miki Castle.  Ultimately, the Bessho were forced to accept a demand to take their own lives in exchange for having spared the lives of their garrison.

Siege of Miki

Lord:  Oda Nobunaga 

Commanders:  Hashiba Hideyoshi, Takenaka Shigeharu (Hanbei), Niwa Nagahide, Takigawa Kazumasu, Akechi Mitsuhide

Forces:  Several tens of thousands

Losses:  Unknown

Commanders:  Bessho Nagaharu, Bessho Yoshichika, Bessho Harusada

Forces:  7,500

Losses:  Bessho Nagaharu and family members took their own lives to spare those of the garrison

The Siege of Miki occurred from 3/29 of Tenshō 6 (1578) to 1/17 of Tenshō 8 (1580) at Miki Castle in Harima Province.  Waged between the Oda and Bessho clans, this is one of numerous battles commanded by Hashiba Hideyoshi of the Oda army in the conquest of Banshū (Harima).  After the Bessho clan holed-up in Banshū-Miki Castle, Hideyoshi severed the supply lines to the castle, imposing hardship on the defenders to force their surrender.

Situation in Harima prior to the battle

During the Muromachi period, the Akamatsu clan served as the military governors of Harima, but after the Kakitsu Disturbance in 1441, were crushed by the bakufu army.  Although the clan later revived, family members and retainers established their own bases of power.  In the late Muromachi period, these families were quasi-independent and competed among one another over several districts.  The Bessho were one of these clans, and as members of the Akamatsu, exercised influence over the eastern portion of Harima.

Harima was located between the spheres of influence of two major clans – the Mōri who were the dominant power in the western provinces (along with the Ukita under their command) and the Oda who were in the process of consolidating control over the Kinai region and expanding to other locations.  The various powers in Harima maintained relations with both the Mōri and the Oda as neither clan controlled the province which served as a buffer zone to maintain peace between the two clans.  After a falling out with Nobunaga, in 1573, Ashikaga Yoshiaki (the fifteenth shōgun of the Muromachi bakufu) turned to the Asakura, the Azai, and the Mōri in a bid to form an alliance to oppose the Oda.  Meanwhile, Kennyo (the eleventh high priest of the Hongan Temple) appealed to the Mōri for support in a protracted war against the Oda.  Consequently, the Mōri joined the opposition camp to the Oda.

Following quarrels with the Mōri, in the fifth month of 1577, Kodera Masamoto, the lord of Gochaku Castle in central Harima, made clear his opposition to them and joined many other local powers by aligning with the Oda.  In the tenth month, Hashiba Hideyoshi entered Harima as the commander of Oda forces and captured several sites including Fukubara Castle and Kōzuki Castle in western Harima which was held by Ukita Naoie.  He positioned Amago Katsuhisa and Yamanaka Yukimori to defend Kōzuke Castle and, at once, almost all of Harima came under the control of the Oda clan.

The relationship between the Oda and the Bessho, however, deteriorated owing to the slaughter by Oda forces during the capture of Kōzuki Castle and discord arising from a meeting held between Hideyoshi and Bessho Yoshichika that same month at Kakogawa Castle.  In 1578, Hideyoshi entered Harima again for an invasion of the Chūgoku region.  In the second month, Bessho Nagaharu (Yoshichika’s nephew and the head of the Bessho clan) abandoned the Oda and aligned with the Mōri.  Assorted powers in eastern Harima under the influence of the Bessho clan followed suit, with further support from the Miki clan of central Harima (who had many followers of the Jōdo-Shinshū sect) as well as the Uno clan of western Harima.

As a result, the comparatively neutral status previously maintained by the clans in Harima suddenly changed with lines drawn between those siding with the Oda and those aligned with the Mōri.  Nagaharu then decided to hole-up in Miki Castle to await reinforcements from the Mōri, leading to the Siege of Miki.

There are assorted theories regarding the reasons for the defection by the Bessho of the Oda, including the rejection by Hideyoshi of a proposal from Miyake Harutada (a retainer of the Bessho), the concern that they would only be used for the convenience of the Oda while control of Harima would in fact be delegated to Hideyoshi, and displeasure at the prospect of serving under the command of Hideyoshi who came from humble origins despite the origins of the Akamatsu as a clan of renown.  It is further surmised that the Mōri actively encouraged opposition to the Oda as well as Ashikaga Yoshiaki who sought allies against the Oda while taking refuge under the protection of the Mōri.

Course of events

Hole-up by the Bessho

After Bessho Nagaharu holed-up at Miki Castle, he amassed a mixed assemblage of 7,500 persons from across eastern Harima.  This included kokujin, or provincial landowners, who supported the Bessho, their family members, and adherents of the Jōdo-Shinshū sect.  This required a large quantity of provisions which became an important topic for the defenders.  During the battle, provisions were supplied via marine transport by the Mōri who had command of the sea lanes on the Seto Inland Sea and from Miki Michiaki, the lord of Aga Castle.  On the side of the Bessho, provisions were brought ashore at Takasago Castle and Uozumi Castle located on the southern coastline, and by coordinating with other auxiliary castles, traveled via the Kako River and through mountain roads to Miki Castle.

Meanwhile, Hideyoshi contemplated a strategy to capture the auxiliary castles.  On 3/29 of Tenshō 6 (1578), Hideyoshi commenced a siege of Miki Castle.  On 4/1, the Bessho army attacked Reizei Tamezumi (the head of the Shimo-Reizei family) and his son, Reizei Tamekatsu, landlords of nearby Hosokawa-no-shō along with Bessho Shigemune (who remained on the side of the Oda) at Beppu Castle.  Tamezumi and Tamekatsu were killed while Shigemune repelled the attack.  From 4/3 to 4/6, the Hashiba toppled Noguchi Castle to the southwest of Miki Castle.

Around this time, a Mōri army of 30,000 soldiers laid siege to Amago Katsuhisa at Kōzuki Castle in an event known as the Siege of Kōzuki Castle.  Hideyoshi temporarily suspended further operations in eastern Harima and, toward the end of the fourth month, established a base on Mount Takakura to the east of Kōzuki Castle.  Owing to an imbalance in force levels, he could not launch an attack against the Mōri army so the situation became deadlocked.  In the fifth month, Nobonaga dispatched an army of 20,000 soldiers under the command of his lineal heir, Oda Nobutada, but the primary objective of these forces was to encircle the auxiliary castles supporting Miki Castle.  Nobutada, together with his younger brothers, Oda Nobukatsu and Oda Nobutaka, surrounded Kanki, Shikata, and Takasago castles to the west of Miki Castle.  The remainer of the forces led by Niwa Nagahide, Takigawa Kazumasu, and Akechi Mitsuhide headed out to support Hideyoshi but this did not result in a breakthrough against the Mōri.

In the midst of a stalemate, the Oda forces on Mount Takakura prioritized the capture of Miki Castle and withdrew to Mount Shosha.  In the seventh month, following an extended siege, the Mōri clan captured Kōzuki Castle after the leaders of the Amago agreed to take their own lives in exchange for sparing those of the garrison.  Perhaps because the recapture of Kōzuki Castle was the sole objective of the Mōri, or to prevent their supply lines from becoming overextended, the Mōri did not advance further east.  This led the Oda army to recommence operations in eastern Harima.  The Oda forces originally sent to support the Amago at Kōzuki combined with forces led by Oda Nobutada and, from the sixth to tenth months, captured Kanki, Shikata, Uozumi, and Takasago castles.  These forces established a main base on Mount Hirai facing Miki Castle (approximately two kilometers to the northeast of Miki Castle) and built auxiliary positions around the base.  As a result, it became difficult for the Bessho to maintain supply lines to Miki Castle.

Conduct of the siege

In the tenth month, Araki Murashige, a bushō in the Oda army, rebelled, joined sides with the Mōri, and holed-up in Arioka Castle, triggering the Siege of Arioka Castle.  Murashige’s territory in Settsu Province was located across the Rokkō mountains to the south of Miki Castle.  This enabled a new supply route by bringing goods ashore at Settsu harbor and transporting them from Hanakuma Castle via Nibuyama Castle to Miki Castle.  Kuroda Yoshitaka, a commander under Hideyoshi, was sent in an effort to convince Murashige not to rebel, but instead Yoshitaka was incarcerated at Arioka Castle.  Yoshitaka was seized because his lord, Kodera Masamoto, acted in coordination with this rebellion by betraying Nobunaga in favor of the Mōri clan.

On 2/6 of Tenshō 7 (1579), supply lines were tentatively secured, but it was clear that, without further progress, the provisions would run low.  To resolve the situation, the Bessho dispatched approximately 2,500 soldiers to the main base of Hideyoshi on Mount Hirai.  This event is known as the Battle of Hiraiyama.  In terms of numbers of soldiers as well as their position on the terrain, the Bessho were at a disadvantage.  The clash resulted in the death of, among other, Nagaharu’s younger brother, Bessho Harusada, and a defeat for their forces.

In the fifth month, Hideyoshi assaulted intermediate points for the supply of provisions from Settsu including the 明要 Temple on Mount Nibu (Tanjō) and Ōgo Castle.  This interfered with the ability to send provisions to Miki Castle.  Nibuyama Castle was built on top of the mountain.  Owing to alignment with the Bessho, Nibuyama Castle was burned down by Hideyoshi, resulting in the deaths of several thousand monks and children.  In the sixth month, Yakami Castle (defended by Hatano Hideharu), which was a pillar in the opposition to the Oda, was toppled by Akechi Mitsuhide, during which Hideharu was captured and executed.  On 6/13, Takenaka Shigeharu (Hanbei), a commander under Hideyoshi, died at the encampment on Mount Hirai.

On 9/10, the Mōri and Bessho both deployed with plans to provision Miki Castle.  Tani Moriyoshi, a yoriki, or security officer, serving Hideyoshi defended a base at Hirata on the west side of Miki Castle.  The Mōri supply battalion attacked this base and killed him while, on the side of the Bessho, 3,000 members of the garrison led by Yoshichika deployed outside of the castle to the area of Ōmura.  This led to violent clashes with the Bessho losing many bushō including Ōgo Sadanori (the lord of Ōgo Castle in Harima) en route to a defeat.  As a result, efforts to provision the castle failed.  These events are known as the Battle of Hirata and the Battle of Ōmura.

In the tenth month, Ukita Naoie (who had been on the side of the Mōri) defected, thereby severing the route between the main base of the Mōri in Aki and Harima and Settsu provinces.  This prevented the Mōri from providing support to those at Miki Castle.  Hideyoshi issued a proposal for surrender which the Bessho rejected.  In the eleventh month, Arioka Castle defended by Araki Murashige in a parallel rebellion was captured by the Oda.  Just before the fall of the castle, Murashige, on 9/2, Murashige fled the castle upon which the Oda murdered scores of hostages.  He then went from Amagasaki Castle to Hanakuma Castle, attempting to continue the resistance, but was unable on his own to make progress against the Oda which led to his eventual ruin.

By the first month of 1580, the provisions at Miki Castle had already run low, leading to a desperate situation for the defenders.  Meanwhile, the Oda army attacked auxiliary castles.  On 1/6 of Tenshō 8 (1580), the Oda toppled the Miyanoue fortress defended by Nagaharu’s younger brother, Bessho Tomoyuki.  On 6/11, after the Oda captured Takaoyama Castle defended by Yoshichika, only Miki Castle remained in the hands of the Bessho.  Bessho Shigemune was the father of Yoshichika and deputy of Nagaharu who aligned with the Oda instead of joining the rebellion.  On 1/14, he issued a proposal to those inside the castle that the lives of the defenders would be spared on the condition that Nagaharu and his family commit seppuku.

End of the siege

The Bessho accepted these terms and, on 1/17, Nagaharu and his family committed seppuku.  Yoshichika attempted to resist but was killed by those inside the castle, marking the end to a hold-out that had lasted for one year and ten months.  While there are records indicating the lives of those in the garrison were spared, a letter from this period on the side of the Hashiba notes that a certain number of people inside the castle were killed without providing the details.  The status of the situation in the aftermath of the siege is uncertain.  Meanwhile, Kuroda Yoshitaka was rescued by retainers from his incarceration at Arioka Castle and met Hideyoshi again, while Kodera Masamoto lost Gochaku Castle to the Oda army and fled for the protection of the Mōri.  Later, Yoshitaka tendered Himeji Castle to Hideyoshi which then became Hideyoshi’s residence.