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
Conventional warfare by Plato, then found more acceptance in the consolidation of power under the Roman Catholic Church. European monarchs then gained power as the Catholic Church was stripped of temporal power and was replaced by the divine right of kings. In 1648, the powers of Europe signed the Treaty of Westphalia which ended the religious violence for purely political governance and outlook, signifying the birth of the modern 'state'. Within this statist paradigm, only the state and its appointed representatives were allowed to bear arms and enter into war. In fact, war was only understood as a conflict between sovereign states.