Regarding the rapid progression of Kiyomori's career at this time, there is a hypothesis that 'many within the aristocracy believed the theory that Kiyomori was retired Emperor Shirakawa's illegitimate child and this led to his rapid promotion.'
この時期の清盛の出世について「当時の貴族社会の中では清盛を白河上皇の落胤とする説が信じられており、このことが清盛の異例の昇進に強く影響した」という説もある。