The area of present-day Anjō has been continuously occupied since preshistoric times. Archaeologists have found numerous remains from the Japanese Paleolithic period and burial mounds from the Kofun period. During the Nara period, the area was assigned to ancient Hekikai County, and was divided into several "shōen" during the Heian period, largely under the control of the Fujiwara clan or the Taira clan. However, in the Kamakura period, parts of the territory came under the control of the Jōdo Shinshū sect, who challenged the secular authority of the various samurai clans, most notably the Matsudaira clan. During the Sengoku period, numerous fortifications were erected in the area. Tokugawa Ieyasu unified the region and destroyed the power of the Jōdo Shinshū sect in the Battle of Azukizaka (1564). During the Edo period, half of present-day Anjō was controlled by Okazaki Domain and the other half by Kariya Domain under the Tokugawa shogunate with some scattered portions of "tenryō" territory ruled directly by the shogunate. During this period, the area was noted for its production of cotton and textiles.