The Imperial family (at that time called 'Oke') during the Kamakura period was split into two family lines and was best known to be in the state of Ryoto tetsuritsu regarding the succession of Chiten (retired emperor who runs the cloistered government) and Emperor.
日本では、鎌倉時代に天皇家（当時の呼称では「王家」）が2つの家系に分裂し、治天と天皇の継承が両統迭立の状態にあったことが最も著名である。