The Battle of Usubagahara occurred on 3/25 of Tenshō 13 (1585) at Usubagahara in the Shioya District of Shimotsuke Province.  The conflict was waged between the Nasu clan and the Shimotsuke-Utsunomiya clan.

Background

At the beginning of the eighth month of 1584, upon orders of his lord, Yamada Tokinari, the lord of Yamada Castle, invaded the areas of Usuba and Hirasawa in the territory of the Nasu clan.  An account of the Nasu clan notes: “The rice seedlings were cut down and turned into hay for horses.  There were many troubles for the local citizens.”

To intercept them, on 8/18, Fukuhara Suketaka and Fukuhara Sukehiro (father and son) deployed.  The Yamada forces withdrew but left deep enmity between the two opponents.

On 3/8 of Tenshō 13 (1585), Nasu Sukeharu, the head of the Nasu family, invaded Kanazawa in the northern portion of the territory of the Yamada.  In response, Tokinari, together with a senior retainer, Okamoto Ujimune, deployed.  Despite defeating Sawamura Gorō in the vanguard forces of the Nasu, he lost to the main division of the Sukeharu and retreated.

Course of events

In response to an invasion by Nasu forces, Utsunomiya Kunitsuna deployed with a contingent of 2,500 soldiers with the intent of attacking the base of the Nasu clan at Karasuyama Castle.  Upon the advice of Shionoya Yoshitsuna, these forces advanced to the village of Izumi in the Shioya District from which to capture forward operating bases of the Nasu including Sawamura and Sakuyama castles.  Sukeharu also deployed with 1,000 soldiers and the two armies confronted each other at Usubagahara.  Despite inferior numbers, the Nasu army gained the advantage in battle through valiant fighting.  Noting that the Utsunomiya were at a disadvantage, Tokinari, together with sixteen soldiers under the command of the Shionoya family, including Shibutare Shuri and 玉生 Ōuchikura charged forward in a bid to kill Sukeharu but, instead, he was killed by Kanda Jirō, a retainer of the Ashino clan.

In the end, the Utsunomiya fled in defeat and the Nasu emerged victorious.

Aftermath

After prevailing in battle against the Utsunomiya forces at Usubagahara, the Nasu army invaded Shioya.  Yamada Castle, the base of Yamada Tokinari fell in an assault by the Nasu.  During the assault, Yamada Shinzaemon (Tokinari’s a chief retainer) and Kikunomae (Tokinari’s wife), along with eleven lady attendants, attempted to escape the castle.  Shinzaemon, however, was killed by pursuing forces.  Kikunomae and her attendants sought refuge on a mountain known as Hanamidoya, but after further pursuit, joined hands and then leapt from a cliff known as Taikoiwa into a ravine traversed by the Hōki River flowing down from the north.  Thereafter, the site where Kikunomae and her attendants lost their lives was called jūni-gozen, or Twelve Madams.

In the wake of the battle, the Nasu forces further advanced in Shioya, capturing numerous castles from the Utsunomiya including Maki and Otsuhata castles, expanding the territory under their control.  Meanwhile, after incurring the loss of many soldiers, the Utsunomiya became concerned about the alliance between the Nasu and the Hōjō clans, prompting them to move their main base from Utsunomiya Castle to the robust mountain fortress known as Taki Castle on Mount Taki in Hitachi Province.