In August, 1180, MINAMOTO no Yoritomo who had raised an army against the Taira clan was defeated by the Taira side, including Kagechika OBA, in the Battle of Ishibashiyama and fled to Awa Province.
治承4年（1180年）8月、平氏打倒の挙兵をした源頼朝は石橋山の戦いで大庭景親ら平氏方に敗れ、安房国へ逃れた。