Marc Bloch's supreme achievement was to recreate the vivid and complex world of Western Europe from the 9th to the 13th centuries. The author treats feudalism as a vitalising force in European society. He surveys the social and economic conditions in which feudalism developed; he sees the structures of kinship which underlay the formal relationships of vassal and overlord. His insights into the lives of the nobility and the clergy and his deep understanding of the processes at work in medieval Europe, are profound and memorable.