Overview
Mimasaka Province (美作国, Mimasaka-no kuni), often called Sakushū (作州), was a traditional province of Japan located on the island of Honshū. In modern terms most of its territory lies within eastern Okayama Prefecture. Historically it functioned as one of the kuni established under the classical ritsuryō administration and appears on early maps and gazetteers as an identifiable regional unit (old province).
Geography and borders
The province occupied a largely inland, hilly area with river valleys and forests that shaped local economy and settlement. Its recorded boundaries connected Mimasaka with a number of neighboring provinces; for a contemporary view see a mapped outline of its limits here.
Administrative history
Mimasaka emerged as a distinct administrative district in the classical and early medieval periods when the central government organized the country into provinces for taxation, military conscription and census purposes. The provincial capital was located at what later became the city of Tsuyama, the political and commercial center of the region and the site of the kokufu (provincial administration).
During the early modern (Edo) era the area was governed under the domain (han) system, with Tsuyama developing as a castle town that organized local agriculture and craft production. With the Meiji Restoration and the abolition of the han in the 1870s, Mimasaka's territory was integrated into the new prefectural system that formed present-day Okayama Prefecture.
Economy, culture and legacy
The landscape of the former province—mountain ranges, forests and river basins—supported mixed agriculture, timber and local crafts rather than large coastal trade. Cultural identity linked to the old province name persisted in place names, shrine histories and local traditions, and the region remains of interest to historians tracing administrative change in Japan. Visitors today may find remnants of the castle-town layout in Tsuyama and rural communities that reflect the province's historical settlement patterns. For further reading on historical provinces and maps, consult general resources on Japan's regional history (provincial overview).
Although provinces like Mimasaka no longer serve as administrative units, they remain useful categories for historical research, genealogy and the study of regional differences in premodern Japan. Selected archival materials and regional studies continue to reference the name Sakushū when discussing the area's past and its role within western Honshū (island context).