Iwase Province

 is an old province of Japan lasting for a brief period of time in the Nara period in what is now western Fukushima Prefecture.
History.
Iwase Province was created during the reign of Empress Genshō. 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. Some scholars have suggested that this innovation may have been motivated by economic considerations.