His parents were Marie Joseph Ferdinand, Baron of Collaert, a one time adjutant to a Prussian prince, and Marianna Hauben.

[2] At some point he and his older brother Marie Joseph Gerard de Collaert joined the Mattha Dragoon Regiment in the army of the Dutch Republic.

[1] In the 1800 campaign on the Main River, he was under the command of Jean-Baptiste Dumonceau and received two serious wounds while leading two squadrons of hussars against an Habsburg Austrian sortie from Aschaffenburg on 23 November.

[3] After Louis Bonaparte became sovereign of the newly created Kingdom of Holland, Collaert was promoted to major general on 7 March 1806.

[5] He was sent to the Illyrian Provinces where took command of the 1st Brigade of Alexis Joseph Delzons' 1st Division of the Observation Army of Italy.

[6] During the Battle of Leipzig on 16–19 October, Collaert led one brigade in Lhéritier's 1,700-strong 5th Heavy Cavalry Division with Pierre Claude Pajol commanding the corps.

[7][note 1] Formations of the Allied army of Karl Philipp, Prince of Schwarzenberg began crossing the Rhine River at Basel on 21 December 1813.

[8] When he received news of the invasion, Marshal Claude Perrin Victor ordered Édouard Jean Baptiste Milhaud to take the 3,500 troopers of V Cavalry Corps and scout enemy movements.

Meanwhile, his 200-man spearhead captured 12 artillery caissons, reached Colmar, learned Milhaud's corps was due the next day and fell back to join the main force.

As the Allies galloped to safety they found the two lead squadrons of Collaert's brigade blocking their escape route.

[13] He led a brigade consisting of the 22nd and 25th Dragoons in Lhéritier's 6th Heavy Cavalry Division during the Battle of La Rothière on 1 February 1814.

[15] In response to the initial attack by Fabian Gottlieb von Osten-Sacken's Russian army corps, Lhéritier charged but was slowed by wet ground and stopped by intense artillery fire.

[17] At the Battle of Mormant on 17 February 1814, Napoleon's army encountered a Russian force of 2,500 infantry and 1,800 cavalry under Peter Petrovich Pahlen.

When the French cavalry pursuit reached Nangis it routed Anton Leonhard von Hardegg's Austrian division of the Allied V Corps.

In the afternoon Lhéritier and Étienne Maurice Gérard's Paris Reserve combined to defeat the 3rd Bavarian Division in the combat of Valjouan.

Finding 10,000 Allied cavalry under Ferdinand von Wintzingerode drawn up in two lines west of Saint-Dizier, Napoleon crossed the Marne River and routed them, inflicting 1,500 casualties and capturing nine guns.

[20] In the last muster on 15 April, Collaert's brigade in Lhéritier's division still included the 22nd and 25th Dragoons and counted 46 officers and 517 rank and file.

Recruited in November 1814, the 8th Hussar Regiment under Louis Duvivier was made up of raw soldiers of French, Belgian and German nationalities.

Enough troopers rallied to form a single squadron which cooperated with the brigades of Hussey Vivian and John Ormsby Vandeleur later in the afternoon.

[2] He was named commander of North Brabant province but died from the effects of his Waterloo wound on 17 June 1816 at Brussels.