He would take part to several military engagements between 1798–1799, most noteworthy at Novi and Mincio.
He becomes aide-de-camp to general Auguste de Marmont and is promoted to the rank of colonel in 1803, taking part to the siege of Ulm, where he was wounded, before being captured by the enemy at the battle of Judenburg.
Set free after the Treaty of Pressburg at the end of 1805, he spent the next year serving as commander of the French artillery in Dalmatia and then Friuli.
In 1809, he took part to the War of the Fifth Coalition and was promoted to brigadier general; after the end of the campaign in Austria, he was given the command of the prestigious horse artillery of the Imperial Guard.
He was promoted to general of division in November 1813 and in 1814, during the Campaign of France, he was given the command of the artillery of the Army of Lyon, under Marshal Pierre Augereau.
During the Hundred Days, Desvaux joined Napoleon and was given command of the entire Guard artillery.
He was killed in action at the battle of Waterloo.
His name is inscribed under the Arc de Triomphe, Northern Pillar.