He fought in the battle of Arcole in Italy under Napoleon, and participated in the Siege of Kehl.

During the Republican Year VIII (1799–1800), the Consular Government sent Chambarlhac into the Vendée against the Chouans, as described in a letter addressed to the first Consul on 8 Pluviôse by Lefebvre (commander of the 15th and 17th military divisions).

On 19 Frimaire, year XII (1802), the first consul nominated him a member of the Legion of Honour and on 25 Prairial, commander of the Order and elector of the Haute-Loire department.

Chambarlhac commanded the 24th Military Division at Ghent during the ultimately unsuccessful Walcheren Campaign.

In early 1813, while commander at Brussels, Chambarlhac formed a special corps for soldiers who were separated from their units, and rejoined the army in Saxony.