 The area then came under the control of the Kudō clan, who were retainers of the Minamoto.During the Muromachi period, the Kudō clan was weakened by internal conflict between supporters of Emperor Go-Daigo and the Southern Court and supporters of the Ashikaga shogunate and the Northern Court, and were thus displaced by the Nanbu clan, who had already been established to the north.During the late Sengoku period, Nanbu Nobunao pledged fealty to Toyotomi Hideyoshi at the Siege of Odawara in 1590 was confirmed as "daimyō" over all of the Nanbu territories, including lands around the site the site of old Kozukata Castle in Morioka.