During the Nara period, the area was assigned to Atsumi, Hoi and Yana Districts of Mikawa Province and prospered during subsequent periods as a post town on an important river crossing of the Tōkaidō connecting the capital with the eastern provinces. During the Sengoku period, the area was a highly contested zone between the Imagawa clan based in Suruga Province and various local warlords, who built a number of fortifications in the area, including Yoshida Castle. The rising power of the Matsudaira clan and its alliance with Oda Nobunaga eventually neutralized the threat posed by the Imagawa, and the area became part of the holdings of Tokugawa Ieyasu. Following the Battle of Odawara in 1590, Toyotomi Hideyoshi ordered the Tokugawa clan to relocate to the Kantō region and assigned the castle to Ikeda Terumasa. Ikeda developed the surrounding castle town and embarked on a massive and ambitious plan to rebuild Yoshida Castle. However, following the Battle of Sekigahara, he was relocated to Himeji Castle.