After her sons Yoriie (head of the Kamakura Shogunate after Yoritomo), and Sanetomo were killed, she became guardian of the young puppet shogun, FUJIWARA no Yoritsune, although in fact she held the real power and was known as the Ama Shogun.
頼朝の跡を継ぎ鎌倉幕府の征夷大将軍となった嫡男頼家、次男実朝が相次いで暗殺された後は、傀儡将軍として擁立された幼い藤原頼経の後見となって幕政の事実上の実権を握り、俗に尼将軍と称された。