The reason for this was, rather than the fact that Yoritomo was a direct descendant of the Minamoto clan among Seiwa Genji, that he had the legacy of Kawachi Genji whose vassals were warriors of the eastern provinces and that there were political stakes among the warriors of the eastern provinces who were dissatisfied with the Taira family.
それは頼朝が清和源氏の中で嫡流であったかというよりも、東国武士を臣下としてきた河内源氏の遺産と、平家に不満のあった東国武士との政治的利害関係があればこそである。