First period, from A.D. 811-1241 -- Second period, from A.D. 1241-1536, the introduction of the Reformation -- Third period, from A.D. 1536-1660; the acknowledgment of Lutheranism until the introduction of Absolute Sovereignty -- Fourth period, from A.D. 1660-1863; (from the introduction of the Absolute Sovereignty till the conclusion of the war with the rebellious duchies).