Toshima

The Toshima were a warrior house of southern Musashi, belonging to the Taira-surnamed Chichibu clan. In 1023 Chichibu Takesune received Toshima district and Kasai, and his line took the name Toshima.

In 1180 Kiyomoto and his son Kiyoshige joined Minamoto no Yoritomo and became Kamakura gokenin; Kiyoshige founded the Kasai clan. In 1333 some clansmen died with the Hōjō at Rokuhara, while others fought under Nitta Yoshisada at Bubaigawara. The Toshima joined the Heiikki league, whose revolt was crushed by the Uesugi in 1368; their lands were confiscated and they later moved to Shakujii Castle.

In 1477 the clan head Yasutsune backed Nagao Kageharu's rebellion and was defeated by Ōta Dōkan. Shakujii and Hiratsuka castles fell by 1478, and Yasutsune vanished, ending the main line. Descendants served the Later Hōjō and the Tokugawa.