Maurice de Saxe
During the War of the Austrian Succession, Armand entered the French army at the end of 1745 as a cornet in the régiment Lameth-Cavalerie. His first battle, aged 14, in 1746, at the siege of Mons, under marshal Maurice de Saxe. Then he took part in the battle of Rocourt and the battle of Lauffeld, in 1746 and 1747. He continued serving in the army until the Treaty of Aix-la-Chapelle (1748).