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, Duke of Opava of Opava after Bolko's death from the latter's brother Nicholas I and in 1464, he purchased the other 2/3 in Opole in 1464 from John II, thereby considerable increasing his political and economic influence in Silesia. William of Troppau died in 1452. He was buried in the Holy Spirit Church in Opava. William was married with Salome, a daughter of the East Bohemian nobleman Půta III of Častolovice and his wife, Anna, the daughter of Albert of Koldice. They had the following children: William, Duke of Opava Duke William of Opava (; – 15 August 1452) was a member of