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.
William V, Duke of Aquitaine William V, Duke of Aquitaine William the Great (; 969 – 31 January 1030) was duke of Aquitaine (as ) and count of Poitou (as or III) from 990 until his death. Upon the death of the emperor Henry II, he was offered the kingdom of Italy but eventually declined to contest the title against Conrad II. He was the son and successor of William IV by his wife Emma of Blois, daughter of Theobald I of Blois. He seems to have taken after his formidable mother, who ruled Aquitaine as regent until 1004. He was a friend to Bishop