Yoritomo ascended to a high official rank, but it was Emperor Goshirakawa who intended that he recognize the establishment of the shugo system; it was not something Yoritomo did without sanction.
頼朝が高い官位に昇り、守護の設置を認められたのは、後白河天皇の意思であり、頼朝が勝手に盗んだものではない。