The evil left-side minister, Yorinaga Fujiwara, and the abdicated emperor, Sutoku, rebelled against Goshirakawa and the former emperor Toba's mistress, Mifukumonin. The insurgents lost the Hogen War. Political power shifted to the winners of the Hogen Rebellion, the lower secretary, Shinzei Fujiwara. The young nobleman, Nobuyori Fujiwara, believed Shinzei did not take him seriously. The head of the Minamoto tribe, Yoshitomo, felt inferior to Kiyomori Taira in the new government. Nobuyori and Yoshitomo imprisoned the emperor Nijo and the abdicated emperor Goshirakawa. They dared to overthrow the government. The two samurai tribes, Taira and Minamoto, fought the Heiji battle. The Fujiwara aristocracy, who had dominated politics for over 400 years, relinquished its power. Kiyomori Taira defeated Yoshitomo Minamoto. Kiyomori became the new powerful man in the government. The aristocratic Heian era came to an end.