Claude de Mesmes, comte d'Avaux (like Rafał Leszczyński). Count d'Avaux concluded treaties between France and Sweden in 1638 and 1641, and during the years 1643–1648, he took part in the lengthy negotiations which led to the Peace of Westphalia, which ended the Thirty Years' War. However, d'Avaux was removed from the Congress of Westphalia in 1648, largely due to ideological differences and competition with the other French diplomats and with his superiors in France. Although this affair damaged his reputation, he ended his life serving the French government as a member of the high Council of the Realm. Claude de Mesmes, comte d'Avaux Claude de
Treaty of Xanten in Westphalia to be governed by the House of Hohenzollern, and were the oldest constituents of the future Prussian Rhineland and the future Province of Westphalia. Treaty of Xanten The Treaty of Xanten () was signed in the Lower Rhine town of Xanten on November 12, 1614 between Wolfgang Wilhelm, Count Palatine of Neuburg and John Sigismund, Elector of Brandenburg, with representatives from England and France serving as mediators. The treaty ended the War of the Jülich Succession and all hostilities between Wolfgang William and John Sigismund. Based on the terms of the treaty, the territories of Jülich-Berg and Ravenstein