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
Duchy of Limburg Eighty Years' War, ended by the 1648 Peace of Westphalia. An area known as Limburg of the States, consisting of parts of Overmaas (but no part of the Duchy of Limburg itself), was ceded to the Dutch Republic. In 1661, the Dutch and the Spanish agreed on a re-partition of the county of Dalhem. The duchy of Limburg itself remained undivided under Spanish Habsburg rule as part of the Southern Netherlands, passing to the Austrian Habsburgs under the Treaty of Utrecht in 1713. When the region was occupied by the French in 1794, the Austrian duchy of Limburg proper was