In 1051 Yoritoki led an army of Emishi into northern Miyagi and defeated a government army at Onikiribe that had been sent to stop the raids. This event triggered the Former Nine Years' War (Zenkunen War).
In 1051, Yoritoki led an Emishi army into northern Miyagi and defeated a government force at Onikiribe to prevent raids. This confrontation initiated the Former Nine Years' War (Zenkunen War).