Sunpu Castle
Tanaka Castle was built by the Imagawa clan as a subsidiary fortification guarding the eastern approaches to Sunpu Castle and was greatly expanded by the Takeda clan after they occupied Suruga Province. After the defeat of the Takeda clan, the castle came under the control of Tokugawa Ieyasu. In 1590, the Tokugawa clan was transferred to the Kanto region by Toyotomi Hideyoshi, who awarded the castle to his retainer, Nakamura Kazutada. Ieyasu regained control after the defeat of the Toyotomi forces at the Battle of Sekigahara.