In 1794, he entered the service of Austria as aide-de-camp to the Prince von Waldeck. The same year he joined the Mortemart regiment (of his uncle the Duke de Mortemart) of the French émigré army. With the restoration of the House of Bourbon, he was appointed Adjutant-Major of the King's Swiss Guards, and he received the cross of the military order of Saint Louis. During the Hundred Days, he followed Louis XVIII into exile; as a reward, he was later promoted to the rank of Lieutenant Commander of the French Column of the Royal Swiss. In 1815, he was raised to the Hereditary Peerage with the title of Marquis. He later refused to swear allegiance to Louis Philippe and resigned his commission in 1830.