This first comprehensive biography of Henry I, the youngest son of William the Conqueror and an elusive figure for historians, offers a rich and compelling account of his tumultuous life and reign. Judith Green argues that although Henry’s primary concern was defence of his inheritance this did not preclude expansion where circumstances were propitious, notably into Welsh territory. His skilful dealings with the Scots permitted consolidation of Norman rule in the northern counties of England, while in Normandy every sinew was strained to defend frontiers through political alliances and stone castles. Green argues that although Henry’s own outlook was essentially traditional, the legacy of this fascinating and ruthless personality included some fundamentally important developments in governance. She also sheds light on Henry’s court, suggesting that it made an important contribution to the flowering of court culture throughout twelfth-century Europe.