The Normans were some of the most feared warriors of the High Medieval period, descended from the Vikings who had settled in Northern France under their leader Rollo in or around 911: throughout the following centuries they built on their warlike reputation. This culminated in their conquest of England under Duke William I. This conquest was by no means assured even after the climactic victory of the battle of Hastings. In order to consolidate his position, William built a series of fortifications around the country. This book covers all these developments from the early days of William I through to the fortifications of Henry II, Richard I and John.