About William IV, Count Of Julich
William IV, Count of Jülich (c. 1210 – 16 March 1278) was the son and heir of William III of Jülich and Mathilde of Limburg, daughter of Waleran III, Duke of Limburg. William's father joined the Crusades in 1217 and died in the Siege of Damietta in 1218.