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 the Conqueror in either late 1039 or October 1040, Gilbert of Brionne took charge of William. Gilbert was killed within months, and another guardian, Turchetil, was also killed around the time of Gilbert's death. Yet another guardian, Osbern, was slain in the early 1040s in William's chamber while the duke slept. It was said that Walter, William's maternal uncle, was occasionally forced to hide the young duke in the houses of peasants, although this story may be an embellishment by Orderic Vitalis. The historian Eleanor Searle speculates that William was raised with the three cousins who later became important in his career