The history of the region from the Kamakura period to the beginning of the Edo period is difficult to piece together, in part because much of the area was destroyed as a result of Kobayakawa Takakage's campaign to subdue Iyo Province during the Invasion of Shikoku.
During the tumult of the establishment of the Tokugawa Shogunate, Saijō was ruled by a series of lords until the establishment of Saijō Domain (Saijō-han) in 1636.