However, being afraid that independent political power existed to the north of the Kanto region, in August that year, MINAMOTO no Yoritomo dispatched his troops to the Oshu region, officially accusing the clan of having sheltered Yoshitsune for a long time.
しかし、関東の後背に独自の政権があることを源頼朝は恐れたため、源頼朝は同年7月、義経を長らくかくまっていた事を罪として奥州に出兵。