Cloistered rule (院政, insei, lit. "monastery administration") was a form of government in Japan during the Heian period. In this bifurcated system, an emperor abdicated, but retained power and influence. Those retired emperors who withdrew to live in monasteries (in) continued to act in ways intended to counterbalance the influence of Fujiwara regents and the warrior class.[1] Simultaneously, the titular emperor, the former emperor's chosen successor, fulfilled all the ceremonial roles and formal duties of the monarchy.
Retired emperors were called Daijō Tennō or Jōkō. A retired emperor who entered a Buddhist monastic community became a Cloistered Emperor (Japanese 太上法皇 Daijō Hōō).
There were retired emperors, including cloistered emperors, both before and after the Heian period, but the notion of cloistered rule as a system usually refers to the practice put in place by Emperor Shirakawa in 1086[2] and followed by his successors until the rise of the Kamakura shogunate in 1192.[1]