Territorial evolution of France face up to the formidable challenge with which they were presented. The Duke of Normandy William the Conqueror became King of England in 1066 through his victory at Hastings over the Saxons. On the extinction of his male line of descent, his heir was the Duke of Anjou, Henry Plantagenet, grandson by his mother of Henry I of England. Two months before he ascended to the English throne, as Henry II, he married Eleanor, Duchess of Aquitaine, the richest heiress in the French kingdom and ex-wife of the King of France. The kings of France nevertheless, held some trump cards:
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