[1] At the Battle of Loano on 23 and 24 November 1795,[3] he and Colonel Jean Lannes led 200 grenadiers against an enemy redoubt armed with six cannons.

For this exploit, his army commander Barthélemy Louis Joseph Schérer named him chef de bataillon (major).

[1] On 11 April 1796, as a junior officer on Amédée Emmanuel Francois Laharpe's staff, Marchand accompanied Napoleon Bonaparte as the new army commander scouted the terrain before the Battle of Montenotte.

[2] In the War of the Third Coalition, Marchand commanded a brigade in Pierre Dupont de l'Etang's division of Marshal Michel Ney's VI Corps.

In the Ulm Campaign, he fought at the remarkable Battle of Haslach-Jungingen, where Dupont's 5,350 infantry, 2,169 cavalry, and 18 guns held off 25,000 Austrians.

[5] During the War of the Fourth Coalition, Marchand commanded the 1st Division in Ney's VI Corps at the Battle of Jena on 14 October 1806.

[11] As the French advanced into Poland, they clashed with the Russians and Prussians in a series of actions, the most prominent of which was the Battle of Czarnowo on 23 and 24 December 1806.

At 5:00 PM, Christoph Friedrich Otto Diercke's Prussian brigade turned up and attacked Soldau but was repulsed after stiff fighting.

[14] Levin August, Count von Bennigsen fell upon the 17,000 soldiers of Ney's VI Corps with 63,000 Russians on 5 June 1807.

At the Battle of Guttstadt-Deppen, Ney fought a brilliant rear guard action before retreating behind the Pasłęka (Passarge) River.

[15] Marchand's division was deployed north of Dobre Miasto (Guttstadt) while Baptiste Pierre Bisson defended to the south.

At 5:30 PM, Emperor Napoleon ordered a 20-gun battery to fire a salvo, signalling Ney to attack Bennigsen's left flank.

As the soldiers hesitated, Bennigsen hurled a mass of cavalry at Bisson's left flank, causing Ney's corps to recoil.

[21] In early 1809, Ney campaigned in Galicia but his 17,000 French soldiers had their hands full trying to control 10,000 square miles (26,000 km2) of territory.

Pedro Caro, 3rd Marquis of la Romana with 1,500 regulars[23] and 8,000 militia attacked Antoine Louis Popon de Maucune's 3,000-man brigade, inflicting 500 casualties.

With Ney's troops, plus the II and V Corps, Soult planned to sweep south and destroy Arthur Wellesley's British army.

[26] When Spanish guerillas captured a French dispatch, the British general found out that Soult was coming down from the north with three corps.

[27] During these operations, Ney's advanced guard clashed with a column under Robert Wilson at the Battle of Puerto de Baños on 12 August, but Marchand's troops were not engaged.

[28] In the fall of 1809, the Spanish army of Diego de Cañas y Portocarrero, Duke del Parque launched an offensive against the VI Corps.

Maucune's attack made considerable progress, but Marcognet's assault stalled in the face of heavy musketry and the fire of 12 cannons.

Falling into confusion, Marcognet's men finally fled downhill and Marchand had to bring up Mathieu Delabassée's reserve brigade to prevent a rout.

[29] Marchand evacuated his headquarters at Salamanca and retired north to Toro where François Étienne de Kellermann joined him with a dragoon division and some infantry.

Learning that the main Spanish army had been smashed at the Battle of Ocana and fearing retribution, del Parque withdrew toward his mountain refuge.

The French cavalry found del Parque astride a river crossing at Alba de Tormes and mounted a devastating attack.

Most of the fighting was over by the time Marchand's infantry arrived, though they managed to seize the vital bridge and town from the Spanish rear guard.

[34] At the Battle of Bussaco on 27 September, Louis Henri Loison's division led the attack up the main road toward to top of the ridge.

On 14 March 1811, he gave the Marquess of Wellington's famous Light Division a bloody nose in the Battle of Casal Novo.

Sir William Erskine, 2nd Baronet marched his 7,000 troops and six artillery pieces forward in a heavy fog without proper scouts.

Two days later, his infantry flushed the British 85th Foot and the Portuguese 2nd Caçadores out of the village of Pozo Bello into the open, where the two battalions were roughed up by French cavalry.

Fearing that he and his soldiers would be attacked by the enraged Grenoble mob, Marchand's artillery officer, a royalist, offered to surrender to Napoleon if his safety was guaranteed.