He did rule in association with his father, Sayori, during in his father's later years; he assisted his father and the husband of his elder sister (Harumoto HOSOKAWA) in battles with Nagayoshi MIYOSHI (Battle of Eguchi).
父・定頼の晩年から共同統治を行ない、父と共に姉婿に当たる細川晴元を援助して三好長慶と戦った（江口の戦い）。