Feudalism, a term applied to the contractual system of political and military relationships among members of the nobility in Western Europe from the 10th century onwards. The word derives from medieval Latin feodum and is of different origin than 'feud' (cf. German Fehde). Although the reality of feudal obligations differs largely at different times and places, the underlying system is evidently the same: A sovereign lets out lands, so-called fiefs, to his barons and the Church; they let lands in turn to the knights, and the knights to the peasants. Thus a man became a vassal to a lord. The vassal did homage to his lord by swearing an oath of loyalty or fealty. The lord in return granted his vassals justice and protection. This system of mutual obligations from the highest sovereign, the king, down to the lowest sub-tenant gave society the shape of a hierarchical feudal pyramid, in which burghers could hardly be integrated.