Seiwa-Genji established the bakufu (Japanese feudal government headed by a shogun) in Kamakura after MINAMOTO no Yoritomo defeated Taira clan's head family and became widely known as a leader of buke (military authority) through controlling the east Japan for three generations.
清和源氏は源頼朝が平氏本家を打ち破った後鎌倉に幕府を開き、3代にわたって東日本を統治した結果、武家の盟主として広く認められるようになった。