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
Engelbert, Duke of Carinthia Engelbert, Duke of Carinthia Engelbert II (died 13 April 1141), a member of the House of Sponheim, was Margrave of Istria and Carniola from about 1103/07 until 1124. In 1123, he succeeded his elder brother Henry as Duke of Carinthia and Margrave of Verona which he held until his retirement in 1135. Engelbert II was the son of Count Engelbert I of Sponheim (d. 1096) and his wife Hedwig of uncertain descent, maybe a daughter of the Billung duke Bernard II of Saxony. His grandfather Count Siegfried I of Sponheim (d. 1065) came to Carinthia about 1035 as an attendant