While engaging in battles with the Otomo and Shoni clans in northern Kyushu, he added title of Shugoshiki (military governor) of Aki and Iwami to his father's estate of Suo, Nagato, Buzen and Chikuzen, and expanded his power to a part of Higo Province as well.
北九州で大友氏や少弐氏らと合戦を繰り広げながら、父の代の領土であった周防、長門、豊前、筑前に加え、安芸、石見の守護職を兼ねるほかに肥前国の一部にも勢力を広げた。