After the late thirteenth century, the Imperial Court adopted the ryoto tetsuritsu system, a system in which succession to the imperial throne alternated between the two ancestral lines of the imperial family: Emperor Gofukakusa (the Jimyoin line) and Emperor Kameyama (the Daikakuji line).
朝廷では、13世紀後半以降、後深草天皇の子孫（持明院統）と亀山天皇の子孫（大覚寺統）の両血統の天皇が交互に即位する両統迭立が行われていた。