Ujizane was the son of Imagawa Yoshimto and became daimyô following the death of his father at Okehazama in 1560. He suffered the loss of his Matsudaira vassals afterwards by unwisely trading a number of Matsudaira hostages for certain of the Udono clan taken by the Matsudaira. He came to rely on the Asahina clan to maintain order in his troubled domain. Between 1561 and 1565, he felt compelled to execute or quell a number of his men, including Ii Naochika (1562) and Iiô Tsuratatsu (1565). He came into conflict with the Takeda and although Ujizane was the son of Takeda Shingen's sister, the latter invaded Suruga Province in 1568 while Tokugawa Ieyasu attacked Tôtômi. As Ujizane was married to a daughter of Hôjô Ujiyasu, the Hôjô offered the Imagawa clan assistance but could not prevent Sumpu from falling to the Takeda. By then Ujizane had fled to Tôtômi and taken up with the Asahina at Kakegawa castle. He was surrounded by Tokugawa Ieyasu’s troops and surrendered, giving up control of the province in exchange for safe passage to Hôjô territory. Since the Takeda had burned Sumpu, Ujizane went on to Sagami province to await developments. Since the Takeda had firmly established themselves in Suruga and the last Hôjô troops had been ejected in 1571, Ujizane retired to Kyoto in 1575. When the Takeda were destroyed in 1582, Ujizane held out hopes that he might receive Sumpu and Ieyasu supported his case but Oda Nobunaga refused. He eventually joined Tokugawa at Edo, having taken the name Sôkan and the tonsure. Although remembered as a poor ruler, Ujizane was culturally refined and his descendants became masters of ceremonies for the Tokugawa.
- Initial text from Sengoku Biographical Dictionary (Samurai-Archives.com) FWSeal & CEWest, 2005