The Battle of Fleurus, on 26 June 1794, was an engagement between the army of the First French Republic, under General Jean-Baptiste Jourdan, and the Coalition Army, commanded by Prince Josias of Coburg, in the most significant battle of the Flanders Campaign in the Low Countries during the French Revolutionary Wars. Both sides had forces in the area of around 80,000 men but the French were able to concentrate their troops and defeat the First Coalition. The Allied defeat led to the permanent loss of the Austrian Netherlands and to the destruction of the Dutch Republic. The battle marked a turning point for the French army, which remained ascendant for the rest of the War of the First Coalition. The French use of the reconnaissance balloon l'Entreprenant was the first military use of an aircraft that influenced the result of a battle.