Joining in with his older brother Kagechika OBA, Kagehisa participated in the Battle of Ishibashiyama as a Heike (the Taira clan) force to subdue MINAMOTO no Yoritomo and put him to rout.
兄の大庭景親に与同して、石橋山の戦いでは平家方につき源頼朝の討伐に参加し、頼朝を敗走させた。