In the middle of the Heian period, around the late tenth century to eleventh century, development and privatization of rice fields by locally influential farmers called Tato (cultivators) were accelerated.
平安時代中葉の10世紀後期から11世紀の頃、地方の有力農民である田堵（たと）による田地開発とその私有地化が活発化した。