Under the 'Meitoku Compromise,' an agreement reached when the Northern and Southern Courts were unified, the Imperial throne would alternate between candidates from the (Japanese) Northern dynasty (of the Gofukakusa lineage) and the Southern dynasty (of the Kameyama lineage), but in 1412 Emperor Gokomatsu of the Northern lineage broke precedent by enthroning his son Prince (Emperor) Shoko as his successor, in a bid to monopolize the Imperial throne for the Northern dynasty lineage, which provoked hostility among former Southern Court supporters.
南北朝合一時の約束「明徳の和約」では天皇は北朝(日本)系（持明院統）と南朝系（大覚寺統）から交代で出す（迭立）ことになっていたが、1412年（応永19年）に北朝系の後小松天皇の次代として後小松上皇の皇子称光天皇が即位したことをきっかけに、北朝系によって天皇位が独占されるようになったのに反抗して起こった。