However, extending his power caused conflicts and produced tensions between him and other Minamoto clans in Kanto, especially in the Musashi Province, and Yoshitomo competed with MINAMOTO no Yoshikuni, who was his granduncle, and had the main base in Ashikaga, Shimotsuke Province.
しかし、義朝の勢力伸張は関東の他の源氏、特に下野国の足利に本拠を置く義朝の大叔父源義国の勢力と武蔵国などで競合することとなり緊張を生んだ。