Westphalia to be Catholic. Osnabrück was divided almost equally between Catholicism and Protestantism. Parts of Westphalia came under Brandenburg-Prussian control during the 17th and 18th centuries, but most of it remained divided by duchies and other areas of feudal power. The Peace of Westphalia of 1648, signed in Münster and Osnabrück, ended the Thirty Years' War. The concept of nation-state sovereignty resulting from the treaty became known as "Westphalian sovereignty". After the defeat of the Prussian Army by the French at the Battle of Jena–Auerstedt, the Treaty of Tilsit in 1807 made the easternmost portion of today's Westphalia part of the
Treaty of the Pyrenees princess entered France. In addition, the English received Dunkirk, although they elected to sell it to France in 1662. The Treaty of the Pyrenees was the last major diplomatic achievement by Cardinal Mazarin. Combined with the Peace of Westphalia, it allowed Louis XIV remarkable stability and diplomatic advantage by means of a weakened Louis II de Bourbon, Prince de Condé and a weakened Spanish Crown, along with the agreed dowry, which was an important element in the French king's strategy: All in all, by 1660, when the Swedish occupation of Poland was over, most of the European continent was at