Subsequently, after the early Heian Period, there were numerous demotions from nobility to subject status with the aim to reduce the state's expenditure by decreasing the number of Koshin, to remove the political infighting concerning the succession to the imperial throne, and to create high-ranking nobilities that would serve as a buffer for the imperial family.
のち、平安初期以降、皇親を減らして国家の支出を減らす、皇位争いに関する政争を除く、皇室の藩屏となる高級貴族をおくなどの目的で、多くの臣籍降下が行われた。