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 Hubertusburg situation existing before conflict broke out. Treaty of Hubertusburg The Treaty of Hubertusburg () was signed on 15 February 1763 at Hubertusburg Castle by Prussia, Austria and Saxony to end the Third Silesian War. Together with the Treaty of Paris, signed five days earlier, it marked the end of the Seven Years' War. The treaty ended the continental conflict with no significant changes in prewar borders. Austria and Saxony renounced all claims to the Silesian territories ceded to Prussia in the 1742 Treaty of Berlin and the 1745 Treaty of Dresden. Prussia clearly stood among the ranks of the European