William the Conqueror to go on pilgrimage to Jerusalem. Although some of his supporters tried to dissuade him from undertaking the journey, Robert convened a council in January 1035 and had the assembled Norman magnates swear fealty to William as his heir before leaving for Jerusalem. He died in early July at Nicea, on his way back to Normandy. William faced several challenges on becoming duke, including his illegitimate birth and his youth: the evidence indicates that he was either seven or eight years old at the time. He enjoyed the support of his great-uncle, Archbishop Robert, as well as the king of
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,