He served in Italy and on the staff of Eugène de Beauharnais during the Russian campaign of 1812. Taken prisoner during the retreat from Moscow, he managed to escape and rejoin the French army. After the Battle of Lützen in 1813 he was promoted to general of brigade, he took part in the Battle of Leipzig and in 1814 he was promoted to general of division for defending Nogent-sur-Seine. After the fall of Napoleon, Bourmont rallied to the Bourbons.