in 1680 the Dukes of Berg-Kleve-Mark-Jülich died out and after some struggles the Earls of Palatine (they were Prince-Electors) became the new rulers of Düsseldorf. The most important duke of this line was Johann Wilhelm II. (1690-1716), called Jan Wellem. After Johann Wilhelm the Dukes moved to their new seat in Heidelberg, because they also got to rule the Duchy of Bavaria.