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 the Conqueror of the year on which fighting was permitted. Although the Battle of Val-ès-Dunes marked a turning point in William's control of the duchy, it was not the end of his struggle to gain the upper hand over the nobility. The period from 1047 to 1054 saw almost continuous warfare, with lesser crises continuing until 1060. William's next efforts were against Guy of Burgundy, who retreated to his castle at Brionne, which William besieged. After a long effort, the duke succeeded in exiling Guy in 1050. To address the growing power of the Count of Anjou, Geoffrey Martel, William joined with