Soon after he was born, he competed for the position of the Imperial Prince with his younger brother (the second prince, who would later become Emperor Reizei) born the same year and having a different mother, Empress FUJIWARA no Anshi, who was the daughter of Udaijin (Minister of the Right), FUJIWARA no Morosuke.
誕生直後、同年生まれで右大臣藤原師輔の娘で中宮藤原安子が生んだ異母弟で第二皇子の冷泉天皇と皇太子の地位を争った。