Inuyama Castle was the final obstacle against Oda Nobunaga's unification of Owari Province. After Nobunaga had defeated the Imagawa clan at the Battle of Okehazama in 1560, his cousin, Oda Nobukiyo, seized Inuyama Castle with the support of Saito Yoshitatsu on Mino Province. Nobugana recaptured the castle in 1564. After Nobunaga's death, Toyotomi Hideyoshi appointed Ishikawa Sadakiyo as castellan of Inuyama. Ishikawa rebuilt the defenses of the castle in line with contemporary designs and the current shape of the donjon is a result of this reconstruction. After the Battle of Sekigahara, the victorious Tokugawa Ieyasu expelled the Ishikawa clan and turned the castle over to Owari Domain.