As he had a close contact with Empress Bifukumon-in, he became a close adviser of her adopted son Imperial Prince Morihito(later Emperor Nijo), and during the Hogen Disturbance, he joined the Emperor Goshirakawa's side together with his nephew MINAMOTO no Mitsumoto (the first generation of the Toki clan), and wan the battle.
そして、美福門院に近かったことから、その猶子となっていた守仁親王（後の二条天皇）の側近となり、保元の乱に当たっては甥の源光基（土岐氏の祖）と共に後白河天皇方に参加して勝利する。