Starting from the late 10th century or the 11th century, which was the middle of the Heian period, local kaihatsu ryoshu started to donate their private lands (shoen) that they illegally owned to the zuryo (provincial officers such as dominant nobilities, temples, and shrines in the capital) in order to escape from confiscation by the kokuga (provincial government offices).
平安時代中葉の10世紀後期から11世紀以降、地方の開発領主らは法的根拠に欠けた自らの私有地（荘園）を、国衙の収公から逃れるため受領層（中央の有力貴族や有力寺社）に寄進した。