During the late Heian period, territories such as manors were confiscated as punishment for not only rebellions and treacheries but also other serious crimes, the term 'Mokkanryo' was started to be used.
平安時代後期には謀反・大逆以外にも重大な犯罪を理由とした没官処分によって荘園などの所領が没収され、「没官領」という呼称が用いられるようになる。