End of the Heian period Separate imperial courts (In no Chō (院庁) evolved around the retired emperors, and their will was put into effect through offices known as Inzen (院宣) and In no Chō Kudashi Bumi (院庁下文). Cloistered emperors also had their own troops, the Hokumen no Bushi (北面の武士). The creation of these military units led eventually to the rise to power of the Taira clan, who used their membership of these units to gather political and economic power to themselves. 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 Emperor Go-Shirakawa was marked by the Genpei War and the rise of Minamoto no Yoritomo as the first Kamakura shōgun. Table The succession of power in the Insei system was complex. During the Shogunates The establishment of the Kamakura shogunate is taken to mark the beginning of the Kamakura period, but the Insei system was not immediately abandoned. Though the shogunate took over the police force and ruled eastern Japan, the authority of the emperors and retired emperors remained considerable. However, when Go-Toba, a grandson of Go-Shirakawa, sought to overthrow the Kamakura shogunate, his forces were defeated in the Jōkyū War, and the shogunate then took steps to reduce the power (and the finances) of the retired emperors. Even after the Jōkyū War, the cloistered rule system continued to exist, at least formally, for another 200 years. There were movements to take authority back into the hands of the imperial court, such as the Kenmu Restoration attempted by Emperor Go-Daigo, but in general a retired emperor presided as the head of the Kyoto court, with the approval of the shogunate. There were also a few examples of retired emperors supervising their successors much later, during the Edo period. The last person to use the title Daijō Hōō was Emperor Reigen, in 1686. See also Retired Emperor (disambiguation) Cloistered Emperor Daijō Tennō Notes References Hurst, G. Cameron. (1976). " Insei: Abdicated sovereigns in the Politics of late-Heian Japan 1086–1185.' New York: Columbia University Press. ; OCLC 1584089 Nussbaum, Louis-Frédéric and Käthe Roth. (2005). Japan encyclopedia. Cambridge: Harvard University Press. ; OCLC