 At the insistence of her cousin Ernest of Bavaria, who was Archbishop of Cologne, Emperor Rudolph II, King Philip II of Spain and Pope Gregory XIII, she married, on 16 June 1585, to Duke John William of Jülich-Cleves-Berg, who was considered physically unattractive and mentally unstable and was the son and heir apparent of William "the Rich" of Jülich-Cleves-Berg, in an attempt to keep the confessionally wavering duke William in the Catholic camp.The marriage was celebrated lavishly in Düsseldorf, which at the time was ravaged by the Cologne War, and was documented by Dietrich Graminäus in his volume .William the Rich could never overcome the early death of his eldest son Charles Frederick.