Auguste was the illegitimate son of Michel-Louis-Étienne, Count Regnaud de Saint-Jean d'Angély, and of his mistress Marie-Louise Chenié, who died shortly after his birth, he was recognised by his father some months later and adopted by the latter's wife in 1795.[citation needed] Regnaud served as a lieutenant in a regiment of hussars during the campaign of Saxe in 1813. He fought at the Battle of Leipzig, after which he became a member of Emperor Napoleon's personal military staff.[citation needed]