This original and pioneering book examines the role of the castle in the Norman conquest of England and in the subsequent administration of the country. The castle is seen primarily as an instrument of peaceful administration which rarely had a garrison and was more often where the sheriff kept his files and employed his secretariat. In most cases the military significance of the castle was minimal, and only a very few ever saw military action. For the first time, the medieval castle in England is seen in a new light which will attract the general reader of history and archaeology as much as the specialist in economic and social history.