He served in the famed IV Corps commended by Marchal Soult, under the orders of Colonel Joseph Bonaparte (Napoleon's elder brother, and later King of Naples and Sicily and of Spain) first, and soon later, under the orders of Colonel Louis-Léger Boyeldieu (). At the head of the 3rd battalion of reserve Calès did not take part, however, to the first battles of the campaign of Austria (1805) (Battles of Ulm and Austerlitz) and stationed in the camps of Nancy (June 1805), Schiltigheim (March 1806) and Strasbourg (January, May, July 1806).