Belfort Montbéliard, who granted it a charter in 1307. Previously an Austrian possession, Belfort was transferred to France by the Treaty of Westphalia (1648), which ended the Thirty Years' War. The town's fortifications were extended and developed by the military architect Vauban for Louis XIV. Until 1871, Belfort was part of the "département" of Haut-Rhin, in Alsace. The Siege of Belfort (between 3 November 1870 and 18 February 1871) was successfully resisted until the garrison was ordered to surrender 21 days after the armistice between France and Prussia. The region was not annexed by Prussia like the rest of Alsace and
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