The youngest of William the Conqueror's sons, Henry I (1100-35) was never meant to be king, but he was destined to become one of the greatest of all medieval monarchs, both through his own ruthlessness and intelligence and through the dynastic legacy of his daughter Matilda, who began the Plantagenet line that would rule England until 1485. A self-consciously diligent and thoughtful king, his rule was looked back on as the real post-invasion re-founding...