Tōtōmi Province
In 1569, Ieyasu's troops penetrated into Tōtōmi Province. Meanwhile, Shingen's troops captured Suruga Province (including the Imagawa capital of Sunpu). Imagawa Ujizane fled to Kakegawa Castle, which led to Ieyasu laying siege to Kakegawa. Ieyasu then negotiated with Ujizane, promising that if Ujizane should surrender himself and the remainder of Tōtōmi, Ieyasu would assist Ujizane in regaining Suruga. Ujizane had nothing left to lose, and Ieyasu immediately ended his alliance with Takeda, instead making a new alliance with Takeda's enemy to the north, Uesugi Kenshin of the Uesugi clan. Through these political manipulations, Ieyasu gained the support of the samurai of Tōtōmi Province.