It is the later compilations such as "Azuma Kagami" and "Hyakurensho" that give him the title 'Seii Taishogun,' while "Gyokuyo" and "Sankaikoryonukigakiyo" (excerpts from "Sankaiki"), historical documents that were written at the time these events took place, have his title as 'Seito Taishogun.'
「征夷大将軍」としているのは後世の編纂史料である『吾妻鏡』や『百錬抄』だが、同時代の史料である『玉葉』や『三槐荒涼抜書要』〔『山槐記』の抄出〕では「征東大将軍」となっている。