Duke of Normandy as the reign of William II (1035–87), the ruler of Normandy could style himself "prince and duke, count of Normandy" as if unsure what his title should be. The literal Latin equivalent of "Duke of Normandy", "dux Normanniae", was in use by 1066, but it did not supplant "dux Normannorum" until the Angevin period (1144–1204), at a time when Norman identity was fading. Richard I experimented with the title "marquis" ("marchio") as early as 966, when it was also used in a diploma of King Lothair. Richard II occasionally used it, but he seems to have preferred the title duke.
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