He fought at Ratisbonne, Essling and Wagram and was made an officer of the ordinance on 12 February 1811 and put in charge of inspecting the coasts of Holland and Denmark. After his success there he rejoined Napoleon at Posen and took part in the 1812 campaign into Russia, during which he received the title of baron of the empire and a donation of 2,000 francs of revenue from Belgium. Surviving the disasters of the retreat from Moscow, the baron of Mortemart returned to France with his health ruined – he was thus unable to take part in the last events of the following campaign. He fought at Leipzig and Hanau – his conduct at the latter gained him promotion to officer of the Légion d'honneur on 30 November 1813. He returned to France with the army.