Willem van Palts-Simmern (1468–1481) Parents Margaret of Guelders Frederick I, Count Palatine of Simmern Children Siblings John I, Count Palatine of Simmern Stefan van Palts-Simmern Catherine, Countess Palatine of Simmern (1455-1522) Fredrick, Count Palatine of Simmern Rupert, Count Palatine of Simmern