Map of Japanese provinces (1868) with Dewa Province highlighted
Dewa Province (出羽国 Dewa no kuni) is an old province of Japan, comprising modern-day Yamagata Prefecture and Akita Prefecture, except for the city of Kazuno and the town of Kosaka. It was sometimes called Ushū (羽州).
In 708 CE, the land of Dewa-no kuni was administratively separated from Echigo; and the ambit of the province was gradually extended to the north as the Japanese pushed back the indigenous people of northern Honshū.
In 712, Dewa Province was administratively realigned in relation to Mutsu Province (陸奥国); and Empress Gemmei's Daijō-kan continued to organize other cadastral changes in the provincial map of the Nara Period, as in 713 when Mimasaka Province (美作国) was divided from Bizen Province (備前国); Hyūga Province (日向国) was sundered from Osumi Province (大隈国); and Tamba Province (丹波国) was severed from Tango Province (丹後国).
In 1335, Shiba Kaneyori received the Dewa Province as a fief from Ashikaga Takauji.
In the Sengoku Period, the southern region around Yamagata was held by the Mogami clan and the northern part by the Akita clan, both of which fought for Tokugawa Ieyasu at the Battle of Sekigahara.
In the late 19th century, Dewa Province was again administratively reconfigured, this time into Uzen and Ugo.
In the Meiji period, the provinces of Japan were converted into prefectures. The maps of Japan and Dewa Province were reformed in the 1870s.
Media related to Dewa Province at Wikimedia Commons
Coordinates: 39°00′59″N 140°19′02″E / 39.01639°N 140.31722°E