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:
Hoël II, Duke of Brittany in the east and the House of Cornouaille in the west may have further strengthened Brittany at a time when external interference was attempted by William the Conqueror. After Hawise's death in 1072, Hoël acted as regent for his son, Alan IV, until the latter reached his majority in 1084. During his reign he faced several rebellions from Breton nobles. Geoffrey Grenonat of Rennes (a natural son of Duke Alan III of Brittany and thus a half-brother of Hawise) led a revolt and was joined by Ralph de Gael who had returned to Brittany from England after the failure of