As the result of Zenkunen War, (the Twelve-year War of Oshu) Abe clan of Mutsu Province (Oshu, the alternative name of Mutsu Province area) went to extinction, and Kiyohara clan of Dewa Province took control of both Dewa and Mutsu Provinces.
1051年から1062年の前九年の役（奥州十二年合戦）で陸奥の安倍氏(奥州)が滅亡し、出羽国の出羽清原氏が陸奥も支配することになった。