Mitsuhira lived in the period of Jisho-Juei War, and became Gokenin (a Shogunal retainer) of MINAMOTO no Yoritomo, with the establishment of Kamakura bakufu (a feudal government headed by Yoritomo).
光衝は治承・寿永の乱の時代の人物で、鎌倉幕府の成立にともない源頼朝の御家人になった。