Frederick's son and successor Eberhard III (1628-1674), however, plunged into the war as an ally of France and Sweden as soon as he came of age in 1633.
The now sparsely populated country welcomed fugitive Waldenses, who gave great effort to restore it to prosperity, but the extravagance of the duke, anxious to provide for the expensive tastes of his mistress, Christiana Wilhelmina von Grävenitz partly neutralized this benefit.