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.
Guy, Duke of Sorrento Guy, Duke of Sorrento Guy (; born c. 1012) was the duke of Sorrento from 1035, the brother of Guaimar IV of Salerno, father-in-law of William Iron Arm and William of the Principate, and brother-in-law of Humphrey of Hauteville. He was the son of Guaimar III and Gaitelgrima. Guy's place in history is secured primarily through his relations (by blood and marriage), though his own actions were not inconsequential. According to John Julius Norwich, he was a "selfless" prince, exhibiting a "moral sense rare for [his] time and position." His brother conquered Sorrento in 1035 and bestowed it on him