His father Emperor Gosanjo expected that a son born to him and MINAMOTO no Kishi (Motoko), who was not a maternal relative of the Northern House of the Fujiwara clan, would be the promising imperial heir rather than his eldest son Imperial Prince Sadahito (who would later become Emperor Shirakawa), who was a descendant from a branch of the Northern House of the Fujiwara clan.
父・後三条天皇は、傍流とはいえ藤原北家の血を引く長男の貞仁親王（白河天皇）よりも同家と外戚関係を有しない源基子との子供に皇位継承候補者として期待をかけた。