William the Conqueror eldest son. William was the son of the unmarried Robert I, Duke of Normandy, by Robert's mistress Herleva. His illegitimate status and his youth caused some difficulties for him after he succeeded his father, as did the anarchy that plagued the first years of his rule. During his childhood and adolescence, members of the Norman aristocracy battled each other, both for control of the child duke and for their own ends. In 1047 William was able to quash a rebellion and begin to establish his authority over the duchy, a process that was not complete until about 1060. His marriage
William, Duke of Austria Austrian duchies, and Frederick IV, the youngest, Tyrol and Further Austria. William, Duke of Austria William ( – 15 July 1406), known as William the Courteous (), a member of the House of Habsburg, was Duke of Austria from 1386. As head of the Leopoldian line, he ruled over the Inner Austrian duchies of Carinthia, Styria and Carniola as well as the County of Tyrol and Further Austria from 1396 until his death. Born in Vienna, William was the oldest son of Duke Leopold III of Austria (1351–1386) and his consort Viridis Visconti (1352–1414), a daughter of Lord Bernabò of