North Rhine–Westphalia 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". As a result of the Protestant Reformation, there is no dominant religion in Westphalia. Roman Catholicism and Lutheranism are on relatively equal footing. Lutheranism is strong in the eastern and northern parts with numerous free churches. Münster and especially Paderborn are thought of as Catholic. Osnabrück is divided almost equally between Catholicism and Protestantism. After the defeat of the Prussian Army at the Battle of Jena-Auerstedt, the Treaty of
Peace of Westphalia European issues of the time. Scholars of international relations have identified the Peace of Westphalia as the origin of principles crucial to modern international relations, including the inviolability of borders and non-interference in the domestic affairs of sovereign states. This system became known in the literature as Westphalian sovereignty. Although scholars have challenged the association with the Peace of Westphalia, the debate is still structured around the concept of Westphalian sovereignty. Peace of Westphalia The Peace of Westphalia () was a series of peace treaties signed between May and October 1648 in the Westphalian cities of Osnabrück and Münster, largely