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
Henri de La Tour d'Auvergne, Viscount of Turenne for which many modern writers have blamed Turenne, appeared no more harsh a measure than the spirit of the times and the circumstances of the case permitted. The Peace of Westphalia (1648) brought little peace to France, which soon became involved in the civil war of the Fronde (1648–1653). Few of Turenne's actions caused sharper criticism than his adhesion to the party of revolt. The army of Weimar refused to follow its leader and he had to flee into the Spanish Netherlands, where he remained until the treaty of Rueil (March 1649) put an end to the first war of