The Kamakura period saw the Imperial line split into two, the Jimyoin line of Emperor Gofukasa's lineage, and the Daikakuji line of Emperor Kameyama's lineage, and this situation is called "Ryoto Tetsuritsu."
鎌倉時代に皇統は後深草系統の持明院統と亀山系統の大覚寺統のふたつに分裂する両統迭立が起こる。