According to the Mutsu waki, the Abe family, leader of fushu (obedient emishi) conquered other clans and took control of the six counties called oku rokugun (Isawa, Waga, Esashi, Hienui, Shiwa and Iwate). In the 10th century, the official status of the Abe family was declared by the central government for the traditional management of emishi , but their domain was limited to these six counties only.
In the 11th century, Abe no Yoriyoshi didn't pay taxes and fought against the governor of the Mutsu provincial government. He crossed over the Koromogawa River which was the southern border of his domain. He also strengthened his position by entering into matrimonial relations with Fujiwara no Tsunekiyo, an officer of Mutsu government. The central government appointed Minamoto no Yoriyoshi as governor of Mutsu (he was appointed chinju fu shogun (General against emishi) later). The fighting between the Minamoto and the Abe occurred and lasted for 11 years (from 1051 to 1062). It was called zen kunen kassen (the early nine years war). But at last, the participation of the Kiyohara family who ruled the three counties of Dewa (Yamamoto, Hiraka and Ogachi) brought the war to end and the Abe family was defeated. This was a victory for the warriors in eastern Japan led by the Minamoto family who had the titles of lords and vassals, and the victory was only realized with the assistance of the regional power.
The Kiyohara family was appointed General against emishi as a reward of victory in the war. This was the first time for fushu and this meant that the military control of Mutsu and Dewa by the Kiyohara family was recognized by the central government. After that, internal strife arose among the Kiyohara families. Minamoto no Yoshi'ie intervened in this, and as a result the Kiyohara family was defeated. Overall supremacy fell into the hands of Fujiwara no Kiyohira, a son of Fujiwara no Tsunekiyo
