保元之亂
The end of the Heian period was marked by a rapid succession of cloistered emperors, to the point that there were several retired emperors living at the same time. The Hōgen Rebellion, following the death of the Emperor Toba, was an example of direct opposition between an emperor and an emperor emeritus. Finally, the end of the reign of Go-Shirakawa was marked by civil war (the Genpei War) and the rise of Minamoto no Yoritomo as the first Kamakura "shōgun".