Peace of Passau
Ernest's grandson Elector John Frederick I of Saxony forfeited the electoral dignity in the 1547 Capitulation of Wittenberg, after he had joined the revolt of the Lutheran Schmalkaldic League against the Habsburg emperor Charles V, was defeated, captured and banned. Nevertheless, according to the 1552 Peace of Passau he was pardoned and allowed to retain his lands in Thuringia. Upon his death in 1554, his son John Frederick II succeeded him as "Duke of Saxony", residing at Gotha. His attempts to regain the electoral dignity failed: in the course of the 1566 revolt instigated by the robber baron Wilhelm von Grumbach, the duke was banned and imprisoned for life by Emperor Maximilian II.