三河国
A castle was built on the banks of the Toyogawa (river) in 1505 by Makino Kohaku, a retainer of Imagawa Ujichika to secure his foothold on eastern Mikawa Province against the growing power of the Matsudaira clan in western Mikawa Province. Due to its strategic location on a river crossing, the castle was involved in numerous battles during the Sengoku period, changing hands several times, and was destroyed and rebuilt on several occasions. From 1565, the castle came under the control of Tokugawa Ieyasu, who named Sakai Tadatsugu as castellan.