How did cloistered government work during the Heian period?

During the late Heian period, the system of cloistered government, known as insei, emerged as a strategy for retired emperors to reclaim political authority from the Fujiwara family.12

How the System Worked

• Abdication and Cloistering: Emperors would abdicate the throne, often while their successors were still young, and take Buddhist vows. By retiring to a monastery or cloister (in), they escaped the direct control of Fujiwara regents and chancellors who had previously dominated the court through maternal marriage ties.12
• Parallel Administration: The retired sovereign established a separate office, the in no chō, to manage state affairs. While the reigning emperor served as a figurehead, the cloistered emperor wielded actual power behind the scenes.2
• Patronage and Influence: Instead of relying on Fujiwara-linked officials, retired emperors surrounded themselves with a new circle of capable, non-Fujiwara aristocrats and clients. This shifted the power base from matrilineal Fujiwara influence to the patrilineal imperial line.2
• Economic Control: The imperial family used this system to accumulate wealth, becoming the largest holders of private estates known as shōen, which bolstered their financial independence and political standing.2