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 establishing the European Defence Community Plan (1959–1962). European foreign policy was finally established during the third attempt with European Political Cooperation (EPC) (1970). This became the predecessor of the Common Foreign and Security Policy (CFSP). Today the European Union and NATO, and formerly also the Western European Union, all carry out some of the functions which was envisaged for the EDC, although none approach the degree of supranational military control that the EDC would have provided for. Treaty establishing the European Defence Community The Treaty establishing the European Defence Community, also known as the Treaty of Paris, is an unratified treaty signed on 27 May