Lilienthal, Lower Saxony conversion of the Cistercian nuns, it became a Lutheran Women's Convent, and until the end of the Thirty Years' War in 1648 it remained in deplorable conditions. In 1650, the city went through secularization. The land once belonging to the convent, which had become fragmented, developed into the small town of Lilienthal. In 1648, according to the terms of the peace treaty that ended the Thirty Years' War (The Peace of Westphalia), the Prince-Archbishopric was transformed into the Duchy of Bremen, ruled together with the Principality of Verden, which were first ruled in personal union by the Swedish Crown. Queen
Treaty of Xanten in Westphalia to be governed by the House of Hohenzollern, and were the oldest constituents of the future Prussian Rhineland and the future Province of Westphalia. Treaty of Xanten The Treaty of Xanten () was signed in the Lower Rhine town of Xanten on November 12, 1614 between Wolfgang Wilhelm, Count Palatine of Neuburg and John Sigismund, Elector of Brandenburg, with representatives from England and France serving as mediators. The treaty ended the War of the Jülich Succession and all hostilities between Wolfgang William and John Sigismund. Based on the terms of the treaty, the territories of Jülich-Berg and Ravenstein