Napoleon I of France made him an officer of the Légion d’honneur in reward for his good conduct in the 1813 campaign, in which he had become chef de bataillon (promoted 3 October 1813).

Although devoted to Napoleon, Cubières demanded his soldiers should come out against the Acte additionnel aux constitutions de l’Empire, to mark the need for a liberal and reforming government.

Despite that praise he lost his commission after the Hundred Days, but his father's influence at court allowed him to obtain the general receipt of the Meuse département and the cross of the Order of Saint Louis (1820).

Promoted to commander of the Légion d’honneur (21 March 1831), he was made commander-in-chief of the French troops landed at Ancona in the Papal States (9 February 1832) to occupy the town in reprisal for Austrian intervention at Bologna.

Returning to France in 1837 with the rank of lieutenant-general, he next became Minister of War in the 1839 transitional government (31 March-13 May 1839) then in Adolphe Thiers's second cabinet (1 March-29 October 1840).

He attached his name to Paris's fortifications, to the decision to write a history of all France's regiments since Francis I and to the organisation of the chasseurs of Vincennes.

Made a peer of France on 7 November 1839, he took part in the discussions of the Chambre des pairs on taxes and roads before being raised to grand officer of the Légion d’honneur on 27 April 1840.

After leaving the army, general Despans-Cubières was compromised in the Teste-Cubières affair, one of the worst scandals of the July Monarchy.

In the meantime, the 1844 novel The Count of Monte Cristo was published - according to Librairie Générale Française (1995), its character of Fernand Mondego was inspired by general Despans-Cubières.