After the death of Kiyomori, the Taira clan weakened fast, and the capital fell due to the attacks by MINAMOTO no Yoshinaka, and Motofusa schemed to regain the political power he lost at Kiyomori's time by presenting his daughter, Ishi, as the concubine of Yoshinaka.
清盛の死後、平氏が急速に衰退して寿永2年（1183年）に源義仲の攻勢の前に都落ちすると、基房は娘の伊子を義仲の側室として差し出して連携を結んで清盛時代に失った権勢を取り戻そうと画策する。