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The Napoleon Series > Biographies > Biographies

General Jean-Baptiste Dumonceau: The Unblemished General

By Bruno Nackaerts

Jean-Baptiste Dumonceau was born in Brussels on 7 November 1760. He was an architect by trade and had quite a good reputation. (While in the army he designed a number of impressive buildings and there are several articles on his importance as an architect).

He joined the patriots in the Brabantian Revolution as captain and commanded the "Canaries", a volunteer corps from the Namur region. This unit was composed of men who were not allowed into the regular army for being too short, or "unsuited for the hardships of military life" and turned them into a crack outfit. They took their name from their yellow uniforms. Dumonceau became one of the popular heroes of the patriot army for his extreme bravery and daring.

When the Revolution collapsed, he fled to France and became the first chef de bataillon in the Legion des Belges et Liègois réunis. Then he commanded the 1st Batallion de la Legion at Jemappes. In late 1793 he was promoted to General de brigade and served as the military commander of Den Haag. He is credited with designing the campaign plan that allowed Pichegu to take Holland.

He was promoted to lieutenant general of the Batavian republic in 1795 and took part in the defeat of the Anglo-Russian Invasion under the command of Brune. On 19 September 1799, Dumonceau was wounded at the battle of Bergen. He eventually assumes command of the Dutch at the siege of Wurzburg.

In 1805, General Dumonceau commanded the Batavian Corps in the Austerltz campaign. He distinguished himself at the passage of the Danube, Ingolstadt, Donauwerth, Nordlingen and Diernstein.

After the 1805 Campaign, Dumonceau was appointed a member of the Conseil d'Etat attached to King Louis (Bonaparte). He served as King Louis's ambassador in Paris for a short while. During the British invasion of Walcheren, Dumonceau commanded the French forces until superceded by Marshal Bernadotte. He was made the Count of Bergendael by appointment of King Louis and was confirmed by Napoleon. In addition to being made a count, he was promoted marshal in the Dutch army, but his appointment was not confirmed by Napoleon. In 1810, when Holland is incorporated into France, he is "demoted" to General de Division and served as the governor of the 25th Military District.

General Dumonceau participated in the Saxon campaign of 1813 and is credited with saving the French from total annihilation at Kulm, where he is wounded. He was captured at Dresden. After his release he remained in France and played no part in the Waterloo Campaign. After Waterloo, in 1815, till his death on 29 December 1821, he was military counsellor to the Dutch crown.

Jean-Baptiste Dumonceau is little known but has a good reputation. He is called the " le general sans tache" (the "unblemished general") and his name is on the Arc de Triomphe.

His son François was captain in the Red lancers and had a very distinguished carreer in the Dutch army. One of his other sons is credited by some to be the "civilian" who informed Grouchy about the Prussians at Wavre.


Cruyplants, Eugène (Major); Dumouriez dans les Ci-devant Pays-bas Autrichiens Brussels : Editions Boeck; 1912.

Dumonceau, François. Memoires du General Comte François Dumonceau Brussels : Jean Puraye Brepols; 1958.

Fierro, Alfred. Histoire et dictionnaire du Consulat et de l'Empire Paris : R. Laffont; 1995.

Guillaume, G. (General Baron). Histoire des Régiments Nationaux Belges pendant les guerres de la Revolution Française Brussels; 1855.