It was in his time that the main base of the Kawachi-Genji (Minamoto clan) became Togoku (Kanto), and especially the Kawachi-Genji (Minamoto clan) had a strong base in Sagami Province centering on Kamakura, with which it had been associated since the time of his great-great-grandfather MINAMOTO no Yoriyoshi.
河内源氏の主要基盤が東国（関東）となったのはこの義朝の代であり、特に高祖父の源頼義以来ゆかりのある鎌倉を中心とする相模国一帯に強い基盤を持った。