Schmalkaldic War
After Emperor Charles V had defeated a number of revolting Protestant princes in the Schmalkaldic War, he in 1548 issued the "geharnischt" (sharply worded) Augsburg Interim in order to re-integrate the Lutheran movement into the established Catholic Church and to prevent the split of the Empire. To defend their autonomy, several Protestant Imperial States reacted with the 1551 Alliance of Torgau; first of all the Saxon elector Maurice of Wettin, who in the Schmalkaldic War had been a strong supporter of the emperor, but also William IV of Hesse-Kassel, the warlike Hohenzollern margrave Albert Alcibiades of Brandenburg-Kulmbach and his cousin the Prussian duke Albert.