As the cloistered government became established after Emperor Shirakawa, under the concept of the family business that gradually became common in noble society at that time, the imperial throne and the head of the imperial family were separated, by which the head of the family ('chiten no kimi' - the retired Emperor who organizes politics) came to operate the essential imperial authority to designate an heir to the imperial throne.
白河天皇以降院政が定着するとともに、当時貴族社会の中で徐々に一般化しつつあった家職観念のもと、天皇位と天皇家の家督が分離し、家督者（治天の君）となった者が本来の天皇の権限を執行し、皇位継承者を指名（譲国）するようになった。