As to the background of the spread of his legend during the middle ages and in the modern era under the title "Hinomoto Shogun TAIRA no Shinno" as opposed to the title he had assumed himself, "New Emperor," Yukihiko SEKI points out that the legend was passed down with the new title as a means of eliminating the possibility of interpreting the name as representing the potentially divisive and dangerous notion of a separate, independent Bando, thereby facilitating respect for the law, and that it reflects the administrative philospphy of MINAMOTO no Yoritomo who chose to become the head of a separate military administration that could peacefully coexist with the Imperial Court.
「新皇」と名乗った史実に反し「日本将軍平親王」としての伝説が中世近世を通じて流布した背景に、板東の分与・独立という危険な思想を意味する前者を排除し、遵法的存在としての名称に換え伝えたもので、軍事権門として朝廷と併存する道を選択した源頼朝を投影したものだとする関幸彦の指摘がある。