 In 1339 Count Reginald II of Guelders (also styled Rainald), of the House of Wassenberg, was elevated to the rank of Duke by Emperor Louis IV of Wittelsbach.After the Wassenberg line became extinct in 1371 following the deaths of Reginald II's childless sons Edward II (on 24 August, from wounds suffered in the Battle of Baesweiler) and Reginald III (on 4 December), the ensuing Guelders War of Succession saw William I of Jülich emerge victorious.William was confirmed in the inheritance of Guelders in 1379, and from 1393 onwards held both duchies in personal union (in Guelders as William I, and in Jülich as William III).