was a Japanese daimyō (feudal lord) of the Sengoku period. Based in Suruga Province, he was known as ; he was one of the three daimyō that dominated the Tōkaidō region. He died in 1560 while marching to Kyoto to become Shogun. He was killed in the village of Dengakuhazama in Okehazama by Oda Nobunaga. Early life and succession Yoshimoto was born in 1519, the third son of Imagawa Ujichika of the Imagawa clan, which claimed descent from Emperor Seiwa (850–880). His childhood name was Yosakimaru (芳菊丸). His family branched from Minamoto clan by the Ashikaga clan. As he was not the eldest son, he was not an heir to his father's lordship. As a result, the young boy was sent to a temple where his name was changed to or . In 1536, his older brother Ujiteru died suddenly, unleashing successional disputes. His elder half-brother, , tried to seize the lordship, but the clan split into two factions. Yoshimoto's faction argued he was the rightful heir because Yoshimoto's mother (Jukei-ni) was the consort of Ujichika. Genkō Etan's faction disputed this based on Genkō's seniority, and that his mother was a member of the Kushima family. However, the Genkō faction was eliminated in the . Baigaku Shōhō changed his name to Yoshimoto at this point and succeeded the clan. Imagawa Campaigns After Yoshimoto succeeded to family headship, he married the sister of Takeda Shingen of Kai. This allowed Yoshimoto to cement an alliance with the Takeda when he helped Shingen imprison his father, Takeda Nobutora, in 1540. Soon after, Later Hōjō clan invaded into the Suruga province but Yoshimoto defeated Later Hōjō's force. In 1542, Yoshimoto began his advance into Mikawa Province, in an effort to fight the growing influence of Oda Nobuhide in that region, but was defeated in the Battle of Azukizaka (1542). Later in 1548, Yoshimoto defeated Nobuhide in the Second Battle of Azukizaka and continued to expand his territory until 1560. In campaigns over the course of the ensuing decades, Yoshimoto wrested control over the Suruga, Totomi, and Mikawa provinces. In 1552, Shingen's son, Takeda Yoshinobu, married Yoshimoto's daughter. Yoshimoto and the Hōjō clan reached a peace agreement in 1554 with the marriage of Yoshimoto's son, Ujizane, to the daughter of Hōjō Ujiyasu, Lady Hayakawa. In 1554, the Imagawa clan came to the west and built the Muraki Castle in the southeast of Owari, besieging Mizuno