The 'Battle of Montcornet' was fought between French and German forces during the German 'Gelb' invasion of north-eastern France (17/18 May 1940).

The French 4ème Division Cuirassée, under the command of Colonel Charles André Joseph Marte de Gaulle, attacked the German-held village of Montcornet in north-eastern France with more than 200 tanks. The French drove off the Germans but were later compelled to retreat for lack of support and as a result of the Luftwaffe’s intervention.

On 10 May 1940, Germany had launched its substantial 'Gelb' offensive against the Netherlands, Belgium, Luxembourg and France and, after their 'Sichelschnitt' breakthrough in the 'Battle of Sedan' on 13 May, the Germans had driven the French forces into hasty retreat.

On 26 April, de Gaulle had been appointed to the command of the new 4ème Division Cuirassée, and on 12 May, as the Germans were fighting to break through and with the division still not fully assembled (it had three tank battalions, representing less then one-third of its establishment strength), de Gaulle was summoned to headquarters and told to plan and implement an attack designed to gain time for Général d’Armée Robert Auguste Touchon’s 6ème Armée to redeploy from the 'Ligne Maginot' to the Aisne river. This was de Gaulle’s opportunity to implement his particular ideas about armoured warfare, which were at variance with those of the majority of his contemporaries.

On the following day, de Gaulle assumed command of the 4ème Division Cuirassée, which comprised 5,000 men and 85 tanks, and with this led a counterattack on the village of Montcornet on 17 May. Montcornet possessed operational significance as it lay on the roads to Reims, Laon and St Quentin, and was a point of transit for the logistical supply echelons of Generalleutnant Friedrich Kirchner’s 1^st Panzerdivision, one of the three armoured visions of General Heinz Guderian’s XIX Corps (mot.).

As his division advanced, de Gaulle commandeered a number of retreating cavalry and artillery units, and also received an extra half-brigade, one of whose battalions included some Char B1-bis heavy tanks. At 04.14 on 17 May, elements of the 4ème Division Cuirassée advanced on Montcornet. After surrounding the village, at about 12.00, the Char B1-bis tanks came under fire from 37-cm PaK 36 anti-tank guns and from German tanks. Though outnumbered and without air support, de Gaulle’s formation attacked and destroyed a German convoy to the south of the village. de Gaulle lost 23 of his 90 vehicles to mines, anti-tank weapons and air attacks by Junkers Ju 87 single-engined dive-bombers. On 18 May the 4ème Division Cuirassée was reinforced by two fresh regiments of armoured cavalry, bringing de Gaulle’s strength to 150 armoured vehicles.

de Gaulle ordered his infantry to neutralise the German defensive pockets in Chivres and Char D2 medium tanks to secure Clermont-les-Fermes. At about 16.00. de Gaulle ordered a new attack on Montcornet, but as the tank crews had not received detailed maps of the sector and came under fire from 88-mm (3.465-in) dual-role anti-aircraft and anti-tank guns, the attack failed. At about 18,00, German warplanes intervened and the 4ème Division Cuirassée retreated to its original positions. de Gaulle attacked again on 19 May, but his forces were again devastated by dive-bombers and artillery. de Gaulle ignored orders to withdraw and in the early afternoon demanded two more divisions from Touchon, but was refused. Although de Gaulle’s tanks forced the German infantry to retreat to Caumont, the action brought only temporary relief and did little to slow the spearhead of the German advance. It was one of the few successes the French enjoyed while suffering defeats elsewhere across the country. A number of the Char B1-bis tanks had to be abandoned when they ran out of petrol, and others when they sank into swampy ground.

The French lost 23 tanks in the attack, together with a number of other armoured fighting vehicles, and took some 130 German prisoners.