Following the development of the shoen koryo sei (system of public lands and private estates), a part of the tribute paid to the lord of shoen (manor in medieval Japan), which was equivalent to the Kanmotsu for kokuga-ryo (territories governed by provincial government office), was called Nengu (land tax).
荘園公領制の展開に伴って荘園領主への貢納のうち、国衙領でいう官物にあたるものが年貢と呼ばれるようになる。