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
Peace treaty peace treaties known as the Peace of Westphalia. It initiated modern diplomacy, involving the modern system of nation-states. Subsequent wars were no longer over religion, but rather revolved around issues of state. This allowed Catholic and Protestant powers to ally, leading to a number of major realignments. The Korean War is an example of a conflict that was ended by an armistice rather than a peace treaty with the 1953 . The Korean War has never technically ended because a final peace treaty or settlement has not been achieved. A more recent example of a peace treaty is the 1973