The aim of the expedition was to suppress Saigoku-gokenin who supported the Taira clan and who were opposed to Yoritomo and to isolate the Taira clan in the Setouchi region.
また九州進軍は平氏討伐ではなく、頼朝と対立・平氏を援助する西国御家人を鎮圧し、平氏を瀬戸内方面に孤立させる事である。