The economic, political and social system in which peasants in the Middle Ages economy depended on both their land and that of their masters to derive a living.
Upon the fall of the Roman Empire, trade collapse, as the routes for it were not safe. This immobility of the people and the need to defend from attacks led to the Feudal System, with landlords on one side and vassals on the othet, both related through fief , i.e. property of the lord held by the vassal for a fee, usually a part of the yield of the land.