Bloch begins by tracing the word feudalism to Boulainvilliers and Montesquieu, then concedes it was badly chosen, since not every manor was a fief and no complex society is well named by one form of property right. He keeps the label as a convention sanctioned by usage and restates the task: to analyse a social structure and its unifying principles in western and central Europe between the mid-ninth century and the early thirteenth. The portion of the book recovered here argues that this society took shape under siege. Muslim raiders in Italy, Hungarian horsemen, and above all Scandinavian fleets that moved from plunder to settlement produced a disorder the new bonds of dependence answered. Bloch weighs how many Northmen actually stayed in England and Normandy by reading place names, personal names, legal custom and social structure rather than chronicle complaint, and treats the density and origin of settlement as questions still open to evidence.