Aizu

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Aizu 会津
Tsuruga Castle, located in Aizuwakamatsu
Aizu comprises the western third of Fukushima Prefecture
Country	Japan
Prefecture	Fukushima
Area
• Total	5,420.69 km2 (2,092.94 sq mi)
Population  (1 October 2017[1])
• Total	270,648
• Density	50/km2 (130/sq mi)

Aizu (会津) is the westernmost of the three regions of Fukushima Prefecture, Japan, the other two regions being Nakadōri in the central area of the prefecture and Hamadōri in the east. As of October 1, 2010, it had a population of 291,838.^[2] The principal city of the area is Aizuwakamatsu.

It was part of Mutsu Province; the area once was part of Iwase Province created during the reign of Empress Genshō.^[3] The Yōrō Ritsuryo established the Iwase Province in 718 through the division of the Michinoku Province (Mutsu Province). It was composed of five districts of Shirakawa (白河), Iwase (石背), Aizu (会津), Asaka (安積) and Shinobu (信夫). The area encompassed by the province reverted to Mutsu some time between 722 and 724.

During the Edo period, Aizu Domain (会津藩, Aizu-han) was a feudal domain under the Tokugawa shogunate which ruled most of the region from Aizuwakamatsu Castle.^[4] Following the Meiji restoration, it became part of the short-lived Iwashiro Province before becoming a region of Fukushima Prefecture.

Although never an official province in its own right, Aizu has a very strong regional identity.