Alan IV, Duke of Brittany of William the Bastard, Duke of Normandy (later to become known as William the Conqueror) support of rebels in Brittany against Alan's maternal uncle, Conan II. Conan II died in late 1066 during a campaign in Anjou, and was succeeded by Alan's parents, Conan's sister Hawise and her husband Hoel II. Hoel ruled as regent from Hawise's death in 1072 until Alan reached his majority in 1084. To prevent further hostilities during his invasion of England, William I married his daughter Constance to the new duke Alan in 1087. The marriage ceremonies may have taken place in Bayeux in Normandy.
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