William the Conqueror eldest son. William was the son of the unmarried Robert I, Duke of Normandy, by Robert's mistress Herleva. His illegitimate status and his youth caused some difficulties for him after he succeeded his father, as did the anarchy that plagued the first years of his rule. During his childhood and adolescence, members of the Norman aristocracy battled each other, both for control of the child duke and for their own ends. In 1047 William was able to quash a rebellion and begin to establish his authority over the duchy, a process that was not complete until about 1060. His marriage
William of Jumièges "De moribus et actis primorum Normannorum ducum", between c. 996 and c. 1015. This work was commissioned by Duke Richard I, and "was renewed by his half-brother, Count Rodulf of Ivry, and his son Duke Richard II (996-1026)... Dudo's work was taken up by William of Jumièges in the 1050s, who revised, abbreviated and updated his "De moribus" and added an account of the reigns of Dukes Richard II, Richard III (1026-7), Robert I (1027-35), and William II [William the Conqueror]." He finished this by 1060 but added to it later when William the Conqueror had become king of England,