This book provides a comprehensive revision and analysis of Normandy, its rulers, and governance between the traditional date for the foundation of the duchy, 911, and the completion of the conquest led by Count Geoffrey V of the Angevins, 1144. It examines how the Norman dukes were able to establish and then to maintain themselves in their duchy, providing a new historical narrative in the process. It also explores the various tools that they used to promote and enforce their authority, from the recruitment of armies to the use of symbolism and emotions at court. In particular, it also seeks to come to terms with the practicalities of ducal power, and reveals that it was framed and promoted from the bottom up as much as from the top down. Dr Mark Hagger is Senior Lecturer in History, School of History, Welsh History and Archaeology, Bangor University.