Battle of Katsuyama
Date: 10/4 of Eishō 5 (1508)
Location: Katsuyama Castle in the environs of Kōfu in the Yamanashi District of Kai Province
Synopsis: This battle arose out of a succession struggle to the Takeda clan during which Takeda Nobutsuna (the lineal heir to Takeda Nobumasa) was opposed by his father and Aburakawa Nobuyoshi (Nobutsuna’s younger brother of a different mother). Owing to a nighttime attack, Nobutsuna and his backers killed Nobuyoshi and other key members of his faction, enabling Nobutsuna to become the successor to the clan.
Commanders: Aburakawa Nobuyoshi, Iwate Tsunayoshi, Kurihara Masatane, Kawamura Shigeie
Losses: Nobuyoshi, a majority of the commanders, three of Nobuyoshi’s sons, others
The Battle of Katsuyama occurred in the tenth month of 1508 between armies led by Takeda Nobutora and Aburakawa Nobuyoshi, the lord of Katsuyama Castle. The conflict arose out of a long succession struggle in the Takeda family. Nobutora ultimately prevailed and the internal conflict subsided.
Takeda Nobutora’s grandfather was Takeda Nobumasa. Nobumasa’s eldest son, Takeda Nobutsuna, was frail from illness, so Nobumasa favored his second son, Aburakawa Nobuyoshi, and endeavored to have Nobuyoshi become heir to the Takeda family. From the Meiō era (1492 to 1501), the Takeda family split between Takeda Nobumasa and Nobuyoshi in one faction and Nobutsuna and his supporters in the other faction, triggering a series of conflicts over the issue of succession. Although Nobutsuna had the upper hand, in the course of the ongoing dispute, neighboring powers including Hōjō Sōun and Imagawa Ujichika applied pressure on the two factions to reconcile, bringing a temporary period of calm. Nevertheless, the underlying reasons for the dispute remained unresolved.
In 1505, Nobumasa died, and, two years later, Nobutsuna died. As a result, Nobutsuna’s eldest son, Nobutora, inherited the family at the youthful age of fourteen. Having a long-held ambition to become the successor, in 1508, Nobuyoshi rejected the peace with Nobutora and re-opened the dispute. At this time, members of Nobuyoshi’s army included his younger brother, Iwate Tsunayoshi, along with Oyamada Yatarō, Kurihara Masatane, Kawamura Shigeie, the Kudō clan. Nobutora’s army included Anayama Nobutō, Ōi Nobusato, the Imai clan, and members of smaller kokujin, or provincial families, who served as retainers of the Takeda family.
On 10/4 of 1508, Nobutora and his supporters departed from their base at the Kawada residence to launch a nighttime assault against Nobuyoshi at Katsuyama Castle. In this battle, a majority of the key members of Nobuyoshi’s army were killed, including Nobuyoshi himself, in addition to three of his sons (Yakurō, Chinpōmaru, and Seikurō) and Iwate Tsunayoshi, Kurihara Masatane, and Kawamura Shigeie. This finally drew to an end the succession struggle that had persisted from the era of Nobumasa. After the defeat of Nobuyoshi, Nobutora initiated attacks against local families who had been supporters of Nobuyoshi, such as the Oyamada, the Imai, and the Ōi clans until he eventually gained control of all of Kai Province. The clash against the Oyamada in the twelfth month of 1508 is known as the Battle of Bōgamine.
The status of Nobutora as the head of the Takeda clan did not change until he was ousted in a coup d’état by Takeda Harunobu in the sixth month of 1541.