Battle of Neerwinden
On 6 November 1792 he commanded the Reserve of the Left Wing at the Battle of Jemappes. Under his command were two squadrons of Mounted National Gendarmes and a number of grenadier battalions. The French defeat at the Battle of Neerwinden on 18 March 1793, left de Flers commanding an isolated garrison at Breda. After a brief siege, he surrendered the place and was allowed to march out with the honors of war on 3 April.