Iwase Province

is an old province in the area of western Fukushima Prefecture on the island of Honshū. The history of the province started in 718 and ended in 722 or 724.
History.
Iwase Province was created during the reign of Empress Genshō. 
The province was established in 718. The area of the province reverted to Mutsu some time between 722 and 724.