Mimasaka Province

In 713, at the suggestion of Bizen-no-kami Nanten - and Bizen-no-suke Kamitsukeno-no-Kenji the Eita, Katsuta, Tomata, Kume, Mashima, and Oba districts of Bizen Province were separated into a new province, and, and Kamitsukeno-no-Kenji was appointed as the first governor of Mimasaka.

In the Kamakura period, Kajiwara no Kagetoki followed by Wada Yoshimori served as shugo before the province came under the direct control of the Hōjō clan.

No central powerful local clan ever rose to prominence and the province changed hands frequently between warring factions in the Sengoku period.

After his death without heir only two years later, the Tokugawa shogunate assigned most of the province to the Mori clan as Tsuyama Domain.

The Mori moved the capital of the province from the Innoshō area, to their newly built jōkamachi at Tsuyama.

Per the early Meiji period Kyudaka kyuryo Torishirabe-chō (旧高旧領取調帳), an official government assessment of the nation's resources, the province had 766 villages, with a total kokudaka of 263,477 koku.