In 1156, he fought in the Hogen Rebellion with Taira no Kiyomori.
He also fought with Kiyomori in the Heiji Rebellion in 1160 along with his younger brother Minamoto no Yoshiyasu.
However, he switched sides shortly after the rebellion and fought with the Minamoto in the Genpei War two decades later.
Yoshishige was posthumously awarded the title of Chinjufu-shōgun, or Commander-in-chief of the Defense of the North, in 1611, four centuries after his death, by the second Tokugawa shōgun, Tokugawa Hidetada.
He ordained as a Buddhist monk and received the Dharma name Jōnichi (上西).