While the reliability of his career has long been doubted in the historical studies, there are some documents, genealogies and so on which would make us presume that he really existed, and his real image has been clarified by those materials.
その経歴の信憑性は歴史学において長らく疑問視されてきたが、一部にその存在を推定させる文書や系図類が存在し、それにより実像の解明がなされつつある。