Imagawa Yoshimoto

Timeline

1. 1519–1536Zentokuji, Suruga · Suruga ProvinceYoshimoto was a son of Imagawa Ujichika; because his full brother Ujiteru was already heir, he entered Zentokuji temple in Suruga at about age four as a monk, taking the name Baigaku Shōhō (also written Shangaku Shōhō). Under the tutelage of Taiyō Zensai he studied at Kenninji and Myōshinji in Kyoto, acquiring Zen-monk and courtly learning, with no expectation of succession.
2. 1536Fuchū, Suruga Province · Suruga ProvinceIn 1536 his brother Ujiteru died suddenly, and Yoshimoto contested the headship with his half-brother Gengo Eitan, also a monk, in what history calls the Hakuraku disturbance. With the support of Taiyō Zensai and his biological mother Jukyō-ni, Yoshimoto returned to lay life, won, inherited the Imagawa clan and the shugo of Suruga, changed his name to Yoshimoto, and completed the transition from Zen monk to domain daimyo.
3. 1537–1550Suruga · Tōmi · Mikawa · Tōkai regionIn 1537 Yoshimoto married a daughter of Takeda Nobutora (Shingen's elder sister), forming the Kō-Suruga alliance; he at first fell out with the Hōjō but later recovered Kato district through mediation. In 1548 the Second Battle of Azukizaka heavily damaged Oda Nobuyasu; in 1549 he captured Anshō Castle and recovered the hostage Takechiyo (Tokugawa Ieyasu), effectively taking over Okazaki after Matsudaira Hirotada's death. By 1550 the Imagawa held Suruga and Tōmi and dominated Mikawa, becoming the strongest Tōkai power.
4. 1554–1560Okehazama · Owari ProvinceAround 1554 Yoshimoto married his heir Ujizane to a daughter of Hōjō Ujiyasu, forming the Kō-Sō-Suruga tripartite alliance and removing rear concerns. In 1553 he augmented his house laws, rejecting the shogunate's shugo-fudōnyū immunity. In 1560 he led an army into Owari and was surprised and killed by Oda Nobunaga while resting at Okehazama, whereupon the Imagawa domain immediately faltered.