His father purchased a captaincy for him in 1729 and he served in the War of the Polish Succession, seeing action at the 1733 Siege of Kehl and the 1734 Siege of Philippsburg. When the War of the Austrian Succession broke out in 1740 his regiment was stationed in France, so Montcalm, seeking action, took a position as an aide-de-camp to Philippe Charles de La Fare. Montcalm and François Gaston de Lévis (who later served under him in New France) were both in the Siege of Prague. He was promoted to Colonel of the Régiment d'Auxerrois in 1743. He took part in Marshal de Maillebois' Italian campaigns, where he was awarded the Order of Saint Louis in 1744 and taken prisoner in the 1746 Battle of Piacenza after receiving five sabre wounds while rallying his men. He was released on parole after several months' imprisonment, and promoted to Brigadier for his actions during the 1746 campaign. After prisoner exchanges made possible his return to active service, he joined the Italian campaign again in 1747. He was wounded again by a musket ball in the Battle of Assietta, and assisted in raising the Siege of Ventimiglia in October. When Marshal Belle-Isle retired that winter, his army was left under the command of its brigadiers, including Montcalm. The war came to an end in 1748 with the signing of the Treaty of Aix-la-Chapelle. In 1749 he was awarded a rare opportunity to raise a new regiment in peacetime; the Regiment de Montcalm was a cavalry regiment that Montcalm occasionally inspected.