In 789, a large scale conquest of Emishi/Ezo's lands was launched by KI no Kosami, who had been appointed as a Seito Shogun (a general to subdue eastern barbarians) in the previous year.
延暦8年（789年）に、前年征東将軍となった紀古佐美らによる大規模な蝦夷征討が開始された。