Collapse at Toishi
Date: Ninth month of Tenbun 19 (1550)
Location: Toishi Castle in the Chiisagata District of Shinano Province
Synopsis: After making progress during an invasion of neighboring Shinano Province, Takeda Harunobu set his sights on subduing Murakami Yoshikiyo, the sengoku daimyō of northern Shinano. Despite wielding the power of a much larger army, the Takeda forces failed in their attempt to scale the cliffs surrounding Toishi Castle. After encountering fierce resistance from the defenders, the Takeda attempted to retreat only to incur more losses in the ensuing pursuit by the Murakami forces.
The Collapse at Toishi occurred in the ninth month of Tenbun 19 (1550) at Toishi Castle in the Chiisagata District of Shinano Province. This battle was waged between Takeda Harunobu (the nineteenth head of the Kai-Takeda clan and sengoku daimyō of Kai Province, later known as Takeda Shingen) and Murakami Yoshikiyo (the sengoku daimyō of Shinano Province).
After unifying Kai Province under the governance of the Takeda clan, in the ninth month of 1535, Takeda Nobutora, the sengoku daimyō and military governor of Kai, entered into an alliance with the Suwa clan of neighboring Shinano Province. In Shinano, Nobutora also allied with Murakami Yoshikiyo. On 5/25 of Tenbun 10 (1541), based on the three-party alliance between the Takeda, the Suwa, and the Murakami, Nobutora invaded the Saku and Chiisagata districts of Shinano and, at the Battle of Unnotaira, expelled the three families of the Shigeno clan (the Unno, the Nezu, and the Mochizuki) to Kōzuke Province. On 6/14 of Tenbun 10 (1541), Nobutora was, in turn, banished to Suruga Province (governed by the Imagawa clan) by his eldest son, Harunobu, whereupon Harunobu succeeded Nobutora to the headship of the clan. Harunobu altered the diplomatic policies of his father, and, in 1542, the Takeda and Murakami clans promptly reconciled with the Yamauchi-Uesugi clan (the deputy shōgun of the Kantō). After severing the alliance with Suwa Yorishige with whom territory had earlier been divided, Harunobu eliminated Yorishige and annexed the Suwa District of Shinano.
Thereafter, Harunobu made an all-out invasion of Shinano and came into conflict with Ogasawara Nagatoki (the lord of Hayashi Castle and military governor of Shinano), Murakami Yoshikiyo (a member of the kunishū, or group of provincial landowners in Shinano), and Uesugi Norimasa (the deputy shōgun of the Kantō). In the seventh month of 1550, Harunobu defeated Nagatoki and seized control of a majority of the south and central portions of Shinano. Next, aiming to pacify the northern and eastern portions of the province, in the ninth month, Harunobu launched a bid to capture Toishi Castle, an outlying base of Murakami Yoshikiyo, the sengoku daimyō of northern Shinano. In 1548, at the Battle of Uedahara, Harunobu was roundly defeated by Yoshikiyo so that this battle was also motivated by a desire for revenge. Moreover, if the Takeda could topple this castle, the defensive lines of the Murakami army in eastern Shinano would pull-back significantly so this was an important engagement both tactically and strategically.
Assault against Toishi Castle
Toishi Castle was small in size, but had cliffs on the east and west sides, reflective of its name which means grindstone. A cliff to the southwest corner was the only location from which to launch an assault against the castle. The Takeda had a total of 7,000 troops to mount an attack against a total of 500 troops in the castle garrison. Among the 500 defenders, approximately one-half of them were remnants of a prior attack by Harunobu in 1547 that resulted in pillaging at Shiga Castle in the Saku District so their spirits were very high. Those holed-up in Toishi Castle included Gakuganji Masakata and Nunoshita Jinbei, kunishū from the Chiisagata District who sided with the Murakami. A younger brother of Sanada Yukitsuna named Yazawa Tsunayori (Satsuma-no-kami, later known as Yoritsuna) was also affiliated with the Murakami.
On 9/9 of Tenbun 19 (1550), the division in the Takeda army led by Yokota Takatoshi, the commander of the ashigaru, or foot soldiers, commenced an all-out assault by climbing a cliff alongside the castle. As the Takeda troops attempted to scale the cliff, the defenders threw stones and dumped boiling water on them, repelling the attacking troops. On the last day of the month, the Takeda forces halted their assault and, on 10/1, incurred major losses as the rear guard fought during their retreat. According to one account, at this battle, Yokota Takatoshi was said to have been killed in action on 9/1. This, however, conflicts with the account of the battle commencing on 9/9, so it is surmised there was an error in the date so that Takatoshi was killed on 10/1 during the retreat. Takatoshi did not have a son, so he adopted Hara Yasukage, the son of Hara Toratane, a commander of the ashigaru.
To prepare for the risk that Ogasawara Nagatoki, the military governor of Shinano, would take advantage of Harunobu’s assault on Toishi by traversing the Shiojiri Pass to attack the Suwa District, Oyamada Nobuari (Dewa-no-kami) was dispatched to join Takeda Nobushige, Anayama Nobutomo, and Hinata Koreyoshi (Yamato-no-kami) at Shiojiriguchi in Shimosuwa in Shinano. A member of the kunishū from the Tsuru District of Kai, Nobuari incurred injuries during the retreat from Toishi while Ozawa Shikibu and Watanabe Izumo-no-kami from the Gunnai region were killed in action. In 1551, during an attack against the Ogasawara in the Tsukama District, Nobuari lay ill at his base and died in the first month of 1552. After the Collapse at Toishi, Hinata Koreyoshi adopted the same title of Yamato-no-kami and, at the time of the demise of the Takeda clan in 1582, there is an account that his son, Toragashira, guarded Ōshima Castle in the Shimoina District of Shinano. There is also a theory that Koreyoshi died in the battle for Toishi.
In terms of military power, the Takeda army had significantly more forces, but suffered in the face of the fierce resistance by the troops defending the stronghold of Toishi Castle. While the Takeda army struggled, Murakami Yoshikiyo reconciled with the Takanashi clan and then rushed with a main division of 2,000 troops from Katsurao Castle to serve as reinforcements for the defenders so the Takeda forces were caught in-between the forces defending Toishi Castle and the division led by Yoshikiyo. Aware of his disadvantageous position, Harunobu decided to withdraw, but the Murakami army fiercely pursued the retreating forces, resulting in the loss of almost 1,000 soldiers from the Takeda army. Harunobu himself relied upon a body-double to narrowly escape from the pursuing forces.
The battle at Toishi Castle was a major defeat for the Takeda, resulting in the loss of almost 1,000 soldiers including Yokota Takatoshi along with Ozawa Shikibu and Watanabe Izu-no-kami. Gonsuke, a monk at the Rishō sub-temple at the Daigo Temple in Kyōto who, at the time of the battle was staying at the Bunei Temple on Mount Minamihara in the village of Minamihara in the Ina District of Shinano, rumored that as many as 5,000 soldiers in the Takeda army were killed in action.
After the Battle of Uedahara, the Collapse at Toishi is known as the second defeat of Takeda Shingen during his lifetime which was referred to by members of the Takeda family as the Collapse at Toishi.
Fall of Toishi Castle
On 5/26 of Tenbun 20 (1551), Toishi Castle was captured by Sanada Yukitsuna (later known as Yukitaka), a retainer of the Takeda residing in Shinano where he served as a member of the senpōshū, or advance guard, in Shinano for the Takeda.
Yukitsuna was a member of the kunishū, or provincial landowners, based in the Sanada township in the Chiisagata District of Shinano. After the Battle of Unnotaira, Yukitsuna joined Unno Munetsuna by going into exile in Kōzuke, but after Haruobu succeeded Nobutora as the head of the Kai-Takeda clan, Yukitsuna returned to the service of the Takeda. In 1547, Yukitsuna served in the Battle of Otaihara against the Yamauchi-Uesugi clan. In 1550, during the assault against Toishi Castle, Yukitsuna lured members of the Kiyono and Terao clans (kunishū from the Hanishina District aligned with the Murakami) to collude with the Takeda.
In one account, the capture of Toishi Castle by Yukitsuna in 1551 is referred to as the”take-over of Toishi Castle by the Sanada” which likely refers to Yukitsuna’s success in luring opponents to his side. Military chronicles from later eras note that the Yazawa clan who were members of the Sanada family colluded with Yukitsuna which may have been led by Yazawa Tsunayori, a younger brother of Yukitsuna. In the first month of 1553, Harunobu notified Oyamada Toramitsu who was residing at Toishi Castle that he would deploy for the purpose of reviving Toishi while the take-over by Yukitsuna caused damage including by fire that necessitated repairs.
On 6/1, Harunobu deployed to Wakamiko in Kai but the movements of the main division of the Takeda army at this time are uncertain. On 7/2, Harunobu deployed again. Iwao Yukiyori (danjōchū), the lord of Iwao Castle of the Iwao-Ōi clan, a kunishū, or provincial landowner, in the Saku District came to Wakamiko to surrender to Harunobu. After the fall of Toishi Castle, Harunobu made repairs to the castle, positioned Oyamada Toramitsu at Uchiyama Castle and made it a base for governance.
In the first month of 1553, Harunobu deployed in the direction of Toishi for the revival of Toishi. At this time, Oyamada Toramitsu was residing in Toishi, having come from Uchiyama Castle. In the third month, after capturing Fukashi Castle (Matsumoto Castle) and assiging a senior retainer named Baba Nobuharu as the chamberlain, Harunobu toppled numerous castles held by the Ogasawara, and the kunishū aligned with the Murakami submitted to the Takeda. On 4/6, Murakami Yoshikiyo abandoned his main base at Katsurao Castle and, through the assistance of Nagao Kagetora (later known as Uesugi Kenshin) went into exile in Echigo Province. Yoshikiyo, Takanashi Masayori, and other kokujin from the northern and eastern portions of Shinano turned to Kagetora for support, which in turn escalated into the Battle of Kawanakajima between the Takeda and the Nagao (the Uesugi) for control of northern Shinano.