[4] The French army commander Barthélemy Louis Joseph Schérer allowed his divisions to fight in isolation.

French generals Victor, Rusca, Dombrowski, Salme, Grandjean, Jean-Baptiste Olivier and Alexis Aimé Pierre Cambray were wounded, the last fatally.

[9] At the Battle of Novi on 15 August 1799, Grandjean commanded a brigade in Emmanuel Grouchy's division of Catherine-Dominique de Pérignon's Left Wing.

[10] Though holding high ground, Grouchy's division on the left flank was unprepared for the Austrian attack at dawn and was pushed back.

[11] The French lines finally collapsed in the late afternoon and enemy cavalry cut down and captured both Grouchy and Pérignon.

[16] In April 1800, Grandjean transferred to the division of Delmas[2] in Jean Victor Marie Moreau's Army of the Rhine where he served as a brigadier.

[19] Early that morning, the Austrian left center column under Johann Kollowrat and Archduke John blundered into Grouchy's division and the fighting began.

Grouchy ordered a counterattack by the 46th and 57th Line Infantry, followed by a cavalry charge that forced the Austrian advanced guard back into the forest.

[20] Later in the day, Antoine Richepanse's division enveloped the Austrian south flank and attacked Kollowrat's column from the rear.

[21] Caught between the divisions of Grouchy, Richepanse and Michel Ney, Kollowrat's column disintegrated into flight and the archduke only escaped the disaster by hard riding.

In late 1806, he was assigned to a command in Northern Europe under Marshal Édouard Mortier, duc de Trévise.

[2] At the start of 1807, French forces led by Mortier crossed the Peene River and advanced toward Stralsund with two divisions.

For two months there were clashes as the French tightened their investment of the port, but were unable to stop Stralsund from being supplied by sea.

While French troops amounting to one cavalry and three infantry regiments were withdrawn to fight against the Russians, they were replaced by soldiers from the Kingdom of Holland.

[24] Mortier received orders to maintain the blockade with Grandjean's division and march with his other forces to assist in the Siege of Kolberg.

In rainy weather, Mortier drove his adversaries back to Anklam and after a scuffle, the Swedes retreated to the north bank of the Peene on 17 April.

The siege force numbered no more than 14,000 men and 41 artillery pieces at any time and consisted of French, Dutch, Italian, Polish, Rhenish and Württemberger troops.

The French attackers abandoned 54 cannons and withdrew after receiving news of the disastrous Battle of Bailén, having suffered 3,500 casualties.

[28] After a reorganization, Grandjean took charge of the 4th Division in the III Corps under Marshal Bon-Adrien Jeannot de Moncey.

[29] These troops participated in the Battle of Tudela on 23 November 1808, though Grandjean's division did not fire a shot or suffer any casualties.

[32] The III Corps approached the city on the south side of the Ebro River with the divisions of Grandjean, Antoine Morlot and Louis François Félix Musnier.

Ordinarily, a lodgment within a city's walls would prompt the defenders to ask for terms, but the Spanish continued to fight behind barricaded houses and churches.

That day, the 44th Line broke through the defenders and advanced to the center of the city but were then driven back nearly to their starting point after losing 200 men.

[39] Since most of the fighting strength of Aragon was killed or captured in the siege, the two corps of Junot and Mortier rapidly overran the Ebro valley.

His other brigade under Anne Gilbert de Laval was forced to relinquish Alcañiz to a Spanish army under Joaquín Blake on 19 May.

He assumed command of the II Corps division of Louis-Vincent-Joseph Le Blond de Saint-Hilaire after that general was fatally wounded at the Battle of Aspern-Essling.

However, the Austrian army commander Archduke Charles, Duke of Teschen personally directed several cavalry charges which forced the division to withdraw.

Grandjean's division had three infantry brigades supported by four squadrons of the 1st Prussian Hussar Regiment and two Polish horse artillery companies.

During the lengthy siege, French-Allied defenders lost 6,000 killed and wounded, 8,000 desertions, 6,000 sick and 16,000 captured as well as 1,300 artillery pieces.

[1] The following year he joined Napoleon during the Hundred Days and was assigned to lead the 17th Infantry Division in Rapp's V Corps.