With the Army of Italy at the crossing of the Battle of Valvasone (16 March 1797), Dorsenne's heroic conduct was noticed by commander-in-chief, general Napoleon Bonaparte, who promoted him to the rank of chef de bataillon (battalion commander).

[1] In 1805, after Emperor Napoleon created the Imperial Guard, Dorsenne was admitted in this elite unit as a major and displayed remarkable bravery at the Battle of Austerlitz, which would gain him the rank of colonel, on 18 December 1805.

By the end of 1806, Dorsenne had taken command of the prestigious Foot Grenadiers of the Imperial Guard, which he soon had to lead in combat at the bloody Battle of Eylau.

After serving briefly in Spain, when the War of the Fifth Coalition broke out, Napoleon called him back to the newly created Armée d'Allemagne and was given command of the Old Guard Infantry Division.

Paul Thiébault later wrote that Dorsenne was a "conceited imbecile", but in the opinion of Charles Oman his record does not match with the accusations of his jealous subordinate.