The Battle of Jemappes was a decisive battle in the War of the First Coalition (1792-97), part of the French Revolutionary Wars (1792-1802). On 6 November 1792, a French army under General Charles-François Dumouriez defeated an Austrian force on the heights of Jemappes in the Austrian Netherlands, leading to the French conquest of Belgium and the expansion of the war.
The battle was the first true test of the armies of the First French Republic (1792-1804), which had been born less than two months earlier. It secured the gains won by the French after the Battle of Valmy and emboldened the French to continue going on the offensive, confident in their 'universal crusade,' which sought to spread the principles of the French Revolution (1789-99).
The Battle of Valmy, fought on 20 September 1792, was a stunning victory for the ragged armies of the French Revolution. Clustered around an old windmill, French artillery held the heights of Valmy against a half-hearted attack by dysentery-afflicted Prussians, advancing through rain and mud. The battle proved decisive, halting the Prussian invasion which had threatened to destroy Paris, and giving renewed energy to the Revolution. On 21 September, the day after Valmy, the National Convention was emboldened enough to abolish the monarchy and declare the French Republic. 22 September was proclaimed the first day of Year I of the Republic, marking the beginning of a new order. France's wartime fortunes were also reversed after Valmy, as reinvigorated French armies swept into both Savoy and the Rhineland.
In the immediate aftermath of the battle, however, it was not yet clear how decisive the day had been. As night fell over the rain-drenched battlefield, the victorious French under General François Christophe Kellermann (1735-1820) silently withdrew from the heights, knowing that they did not have the numbers to withstand a more spirited Prussian assault. They pulled back to the town of Sainte-Menehould, headquarters of the Army of the North, destroying roads and fields along the way to slow the expected Prussian advance. Yet, no such advance would be forthcoming. The Prussian army, ravaged by dysentery and a dwindling food supply, had become demoralized by the unexpected stiffness of French resolve; this would not be the swift and easy conquest promised by their French royalist allies. Prussian commander Charles William Ferdinand, Duke of Brunswick, proclaimed "hier schlagen wir nicht" ("we will not fight here") and decided to negotiate a retreat.
On 22 September, a certain Colonel Manstein was sent to treat with the commander of the French Army of the North, General Charles-François Dumouriez (1739-1823). A career soldier and occasional politician, Dumouriez had briefly served as French foreign minister from March to June 1792, having used that position to drum up support for the war against Austria. But to Dumouriez's mind, the war was against Austria alone, as the Austrian Habsburgs were deemed by many to be the true external threat to French liberty. Prussia's entry into the conflict as Austria's ally had been an unfortunate development, one that Dumouriez had worked hard as foreign minister to avoid. Eager to get back to fighting the Austrians, Dumouriez found that an opportunity had landed in his lap to remove the Prussians from the war altogether.