Sakai clan
Isesaki developed during the Sengoku period as a castle town surrounding Akaishi Castle, a stronghold in southern Kōzuke Province controlled by the Yura clan. During the Edo period, it was the center of Isesaki Domain, a feudal domain under the Tokugawa shogunate controlled by the Sakai clan. The area also contained two post towns on the Nikkō Reiheishi Kaidō, a subroute to Nikkō Kaidō which connected the Nakasendō directly with Nikkō, bypassing Edo.