 During the years 1622-1623, he created a patriotic federation, the "German Friedbund", for the promotion of the German states and religious liberties.Wilhelm's maternal uncle, Louis I of Anhalt-Köthen, provided the Friedbund with a generous endowment.Wilhelm allied himself with his brothers in the Thirty Years' War, serving under Ernst von Mansfeld and Georg Friedrich, Margrave of Baden-Durlach.