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 the Pyrenees Spanish Habsburg victories in the Dutch Revolt in the 1620s and at the Battle of Nördlingen against Sweden in 1634. By 1640, France began to interfere in Spanish politics, aiding the revolt in Catalonia, while Spain responded by aiding the Fronde revolt in France in 1648. During the negotiations for the Peace of Westphalia in 1648, France gained the Sundgau and cut off Spanish access to the Netherlands from Austria, leading to open warfare between the French and Spanish. After 23 years of war, an Anglo-French alliance was victorious at the Battle of the Dunes in June 14, 1658, but