With the outbreak of the Hōgen Rebellion in 1156, the members of the Minamoto and Taira samurai clans were called into the conflict.

Yoshitomo, defeating his father and the forces of Sutoku and Yorinaga, became head of the Minamoto clan and established himself as the main political power in the capital of Kyoto.

The civil war wasn't to go on for very long as Kiyomori declared his support for the Emperor and rapidly defeated the rebel forces within the span of a month.

[1]: 255–258 While making his escape from Kyoto, Yoshitomo was forced to sacrifice his son Tomonaga to buy time.

His two sons, Yoshihira and Tomonaga, lost their lives following the Minamoto Clan's defeat in the Heiji Rebellion in 1160.