The aim of this campaign was to mop-up the power of Taira forces including Ietsune HASUIKE, Shunto HIRATA and the like, who had killed Yoritomo's younger maternal half-brother, MINAMOTO no Mareyoshi; Yukimune YASU, a gokenin (an immediate vassal of the shogunate) from Tosa Province took the head of the charge.
これは頼朝の同母弟の源希義を殺害した蓮池家綱・平田俊遠ら平家方勢力の掃討を目的としており、土佐出身の御家人・夜須行宗を先導に立てたものだった。