The 'Battle of Arras' was fought between Allied (largely British) and German forces near the near the north-eastern French town of Arras (21 May 1940).

After the German 'Gelb' and associated 'Sichelschnitt' invasions of the Low Countries and France on 10 May, French and British forces advanced into Belgium as part of their 'Dyle Plan'. The initial 'Gelb' plan had evolved into a decoy operation in the Netherlands and Belgium, making the 'Sichelschnitt' armoured thrust through the Ardennes into France the primary German thrust. German formations and units crossed the Meuse river without waiting for reinforcements in the 'Battle of Sedan'. Instead of consolidating bridgeheads on the western bank of the Meuse river, the Germans immediately began an advance down the Somme river valley toward the southern coast of the English Channel. With their best forces located in Belgium, the Allies were thrown into confusion and their attempts to cut off the Panzer spearheads degenerated into sporadic and un-coordinated counterattacks which achieved wholly insufficient concentration to ensure success. The offensive at Arras was planned by the British and French in order to relieve the pressure on the British garrison in the town of Arras, and was not co-ordinated with an attack by the French from the south of the 'Panzer corridor'.

Constrained by the limited forces available to them, the British and French attacks were carried out by small mixed forces of British and French tanks and infantry advancing to the south from Arras. The Allies were successful in making some early gains and panicked a number of German units, but after an advance of up to 6.2 mi (10 km) they were forced to withdraw after dark to avoid encirclement. The attack had been a failure but had a disproportionate effect on Adolf Hitler and Oberkommando der Wehrmacht. Worry about more Anglo-French counterattacks against the 'Panzer corridor' before non-motorised German infantry divisions could come forward to support the Panzer and motorised divisions led Hitler to order a halt to the Panzer advance until the situation at Arras had been restored. The Allies used the pause to reinforce the English Channel ports, prevent their rapid capture and fortify the western approaches to Dunkirk before the Germans arrived, making possible the 'Dynamo' evacuation of the British and some French forces.

Generaloberst Gerd von Rundstedt’s Heeresgruppe 'A' defeated the French in the 'Battle of Sedan' from 12 to 15 May and crossed the Meuse river. A French counterattack at the 'Battle of Montcornet' on 17 May by Colonel Charles de Gaulle’s 4ème Division Cuirassée, from Montcornet to the south, was defeated by an improvised defence and Generalleutnant Ferdinand Schaal’s 10^th Panzerdivision, which was rushed forward on the French flank. The German counterattacks were supported by General Wolfram Freiherr von Richthofen’s VIII Fliegerkorps, and the French lost 32 tanks and armoured vehicles. On 19 May, after receiving reinforcements, the 4ème Division Cuirassée attacked again and was again repulsed with the loss of 80 of its 155 vehicles, much of the loss being caused by the aircraft of the VIII Fliegerkorps, which attacked French units as they massed to fall on the flanks of German units. By the end of the 'Battle of Montcornet', much of Général d’Armée André Corap’s French 9ème Armée on the Meuse river had disintegrated under the attacks of the VIII Fliegerkorps.

German spearheads broke through the gap between Peronne and Cambrai and threatened Boulogne and Calais, cutting the lines of communication of the Allied armies of Général d’Armée Gaston’s 1ère Groupe d’Armées in Général d’Armée Alphonse Joseph Georges’s North-East Theatre of Operations, separating them from the main French armies to the south of the Somme river. On 19 May, General Sir Edmund Ironside, the British Chief of the Imperial General Staff, conferred with General the Lord Gort, commander of the British Expeditionary Force, at the latter’s headquarters near Lens and urged Gort to save the British Expeditionary Force by attacking toward Amiens to the south-west, but Gort had only two divisions available for an attack. Ironside met Billotte, finding him apparently incapable of taking action. Ironside returned to the UK and ordered urgent anti-invasion measures.

On the morning of 20 May, Général d’Armée Maurice Gamelin, the commander-in-chief of the French armed forces, ordered the armies trapped in Belgium and northern France to fight their way to the south in order to link with French forces attacking to the north from the Somme river. On the evening of 19 May, the French prime minister, Paul Reynaud, had sacked Gamelin and replaced him with Général d’Armée Maxime Weygand, who cancelled the orders and after a delay ordered a similar counter-offensive from the north and south against the 'Panzer corridor' to break the encircled armies out of the pocket. In the north the British combined their available divisions with Major General G. Le Q. Martel’s 50^th Division, which was holding the Vimy area, to create Frankforce. This was to hold the line of the Scarpe river to the east of Arras with Major General H. E. Franklyn’s 5^th Division, while the rest of the force attacked to the south of Arras and Général d’Armée Antoine Marie Benoît Besson’s new French 3ère Groupe d’Armées attacked to the north from the Somme river.

King Leopold III of Belgium told Gort that he did not expect the British Expeditionary Force to risk itself to keep contact with the Belgian army, but warned the British that if they persisted with the southern offensive, the Belgians would be -overstretched and collapse. Leopold suggested that the Allies should instead establish a beach-head covering Dunkirk and the Belgian channel ports. The British Expeditionary Force reinforced Arras despite the fact that Gort had doubts about the French plan. Billotte took part in a meeting in Ypres from 19 to 21 May. Driving back after this meeting, he had a road accident, fell into a coma and died soon afterward, leaving the Allied 1ère Groupe d’Armées leaderless for three days. Ay about that time, the British decided to evacuate their forces via the English Channel ports.

Generalmajor Erwin Rommel’s 7^th Panzerdivision had captured Cambrai and advanced to the area south of Arras. For 21 May, the division was ordered to wheel to the west around Arras and attack to the north, capturing crossings over the Scarpe river at Acq, a risky manoeuvre since the right flank would be vulnerable to a counterattack from Arras. Generalleutnant Max Hartlieb genannt von Walsporn (from 22 Generalleutnant Joachim Lemelsen’s) 5^th Panzerdivision was to attack so as to relieve pressure on the 7^th Panzerdivision, which was delayed and never managed to fulfil its orders. Both of these Panzer divisions were elements of General Ewald von Kleist’s Panzergruppe 'von Kleist'. Rommel ordered the 5^th Panzerregiment to probe towards Acq, 6.2 miles (10 km) forward, with two motorised infantry regiments to follow later, which left most of the division without tanks. Rommel led the advance but returned back at 16.00 when the infantry failed to arrive and at the positions of the 7^th Schützenregiment found himself under attack by tanks and infantry.

Georges ordered Général de Corps d’Armée François Pierre Raoul de la Vigerie, commander of Zone d’Opérations Aériennes Nord of the French air force to support the British attack but sent no details of the attack front, targets and start time. d’Astier de la Vigerie was also unable to contact the headquarters of the 1ère Armée or the headquarters of the RAF Air Component of the British Expeditionary Force, which was out of action as it was moving back to bases in England. French reconnaissance aircraft were shot down or chased away until 16.00, when aircraft got through to Arras and found no activity around Cambrai. Franklyn, commander of the 5^th Division, was put in charge of Frankforce, improvised from his division, Martel’s 50^th Division and the 74 tanks of Brigadier D. A. Pratt’s 1^st Army Tank Brigade. Frankforce had moved to the vicinity of Vimy, to the north of Arras, to reinforce the Allied garrison at Arras, for a counterattack to the south, in order to cut German lines of communications in the vicinity. Franklyn had detached a brigade each from the 5^th Division and the 50^th Division, which had only two instead of the usual three brigades each. Franklyn was not aware of a French push to the north toward Cambrai and the French were ignorant of a British attack to the south toward Arras.

Franklyn had support from Général de Corps d’Armée René Prioux’s Corps de Cavalerie of the 1ère Armée, which had fought at the 'Battle of Hannut' (12/14 May) with its SOMUA S35 cavalry tanks. Many of the tanks of the 1ère Division Légère Mécanique had been destroyed in the earlier battles and the rest had been distributed among infantry divisions and could not be reassembled in time for the planned attack despite threats to court-martial officers who refused to release the tanks. By 21 May, Prioux could contribute only a few tanks of Général de Brigade Jean Léon Albert Langlois’d 3ème Division Légère Mécanique. It had been intended that the attack be made by two French and two British infantry divisions, but Frankforce comprised only about 15,000 men after the detachment of brigades to the defence of Arras, to the river to the east and into reserve. The defensive deployments left only the 6 and 8/Durham Light Infantry of Brigadier J. A. Churchill’s 151^st Brigade and one in reserve as well as Brigadier M. B. Beckwith-Smith’s 13^th Brigade, supporting the 4/Royal Tank Regiment and the 7^th Royal Tank Regiment, a force of about 2,000 men and 74 tanks. These infantry tanks were 58 examples of the Matilda I, thickly armoured but armed only with a machine gun, and 16 examples of the Matilda II, very well armoured and carrying a 2-pdr gun and a machine gun.

The original orders to Franklyn had been to plan a limited attack to the south of Arras with the object of relieving the garrison. Changes made by Ironside, to create a more ambitious combined attack with the French, were not communicated to Franklyn, who used most of Frankforce defensively, to reinforce Arras and relieve the Corps de Cavalerie in the area to the east of the town. Martel was ordered to plan an attack to 'clear and capture the area south of the River Scarpe from inclusive southern outskirts of Arras including Pelves and Monchy thence line of Cojeul river as far as Arras-Bapaume.' This was an area of more than 40 sq miles (103.5 km²). A force based on the 151^st Brigade was to advance from the west of Arras and move round to the Cojeul river, and Brigadier M. C. Dempsey’s 13^th Brigade of the 5^th Division was then to cross the river and advance to the south from the eastern side of Arras in order to link with 151^st Brigade. A Right Column (7^th RTR, 8^th DLI, 365^th Battery of the 92^nd Field Regiment, 260^th Battery of the 65^th (Norfolk Yeomanry) Anti-Tank Regiment, one platoon of the 151^st Brigade Anti-Tank Company and one motorcycle scout platoon of the 4/Northumberland Fusiliers) and a Left Column (4/RTR, 6/DLI, 368^th Battery of the 92^nd Field Regiment, 206^th Battery of the 52^nd Anti-Tank Regiment, one platoon of the 151^st Brigade Anti-Tank Company, one company and one scout platoon of the 4/Northumberland Fusiliers) were to cross the road linking Arras and Doullens road at 14.00, which meant that the infantry would have to make an 8-mile (13-km) approach march to reach the jumping-off point, over roads filled with traffic and cluttered with refugees.

An advance by the 3ère Division Légère Mécanique, to screen the right flank of the British force, was also poorly prepared with insufficient liaison: the French were not told of the timing and direction of the British attack. In the confusion an exchange of fire occurred between the French S35 tanks and British anti-tank guns near Warlus: one anti-tank gun was destroyed, British soldiers were killed and several French tanks were hit before the mistake was discovered. During the evening, the French force, with about six S.35 tanks, engaged the 25^th Panzerregiment in the area to the south of Duisans. British troops were retreating and by the time the German tanks broke through, the British had escaped.

The time taken by their infantry to reach the assembly points for the attack left little time for the British to study their orders or to undertake reconnaissance. Maroeuil was being bombarded when 50^th Division began the advance. The Right Column advanced at 14.30 and received small arms fire from a wood. The column had to fight through Duisans, which was occupied by German infantry, and French tanks on the right reported tanks of the 25^th Panzerregiment of the 7^th Panzerdivision to the west. Two companies of the 8/DLI and two troops of the 260^th Anti-Tank Battery were left to garrison the village and the depleted column then took Warlus against stronger opposition and had to leave another garrison. Berneville to the south was also captured and a party of the 7/RTR and 8/DLI pressed on to the road liking Arras and Doullens where it met part of the 7^th Schützenregiment and troops of SS-Gruppenführer Theodor Eicke’s SS Division 'Totenkopf'.

The British were forced under cover by machine gun and mortar fire, and German aircraft attacked the Right Column for 20 minutes. Junkers Ju 87 single-engined dive-bombers of the I and III/Sturzkampfgeschwader 2 attacked British forces at Arras. The I/StG 77 is also known to have attacked infantry positions to the north of Arras. The tanks kept moving and reached Wailly, where they met elements of the SS Division 'Totenkopf'. The advanced guard suffered many casualties and retreated to Warlus, and German tanks counterattacked both Warlus and Duisans. The German attacks were repulsed but nonetheless cut the road between the villages, and the Right Column was unable to advance farther.

The Left Column also met resistance as soon as it advanced, but fought its way through the 6^th Schützenregiment at Dainville. At Achicourt, another 2 miles (3.2 km) farther, six Matilda tanks overran a line of anti-tank guns and the column then advanced to Agny and Beaurains before a party reached Wancourt on the Cojeul river. Infantry garrisoned Agny and Beaurains and the 4/RTR repulsed German armoured counterattacks supported by the 7^th Schützenregiment on the 7^th Panzerdivision's right flank. The British then took ground to the south of Beaurains. Fighting continued right through the afternoon between Mercatel and Tilloy, where the tanks ran into a line of anti-aircraft guns and artillery, including 88-mm (3.465-in) FlaK guns, and many of the tanks were knocked out. Individual tanks kept going but there were no reserves to consolidate and exploit the success, and the advance came to an end in mutually costly fighting. To the east of Arras, the 150^th Brigade attacked across the Scarpe river toward Tilloy and the 13^th Brigade took a bridgehead farther to the east in preparation for the second phase of Franforce’s attack.

The 6^th Schützenregiment was attacked while advancing toward Agny by a British column advancing from Dainville, which knocked out several vehicles. More British tanks attacked from the north and caught the regimental convoys strung out along the road on their right flank. The 42^nd Panzerjägerabteilung was therefore rushed to the area between Agny and Beaurains, but was overrun by the British tanks. After breaking through the 6^th Schützenregiment, the British armour attacked the transport of the 7^th Schützenregiment between Mercatel and Ficheux and then pressed on, throwing the motorised SS Division 'Totenkopf' into confusion and almost overrunning its headquarters. When the British tanks broke through the German anti-tank screen, the infantry stood their ground, encouraged by Rommel, even after the British tanks had rolled over their anti-tank guns.

At about 16.00, the 2/7^th Schützenregiment was attacked by about 40 British tanks, which were engaged by artillery on Hill 111 about 1095 yards (1000 m) to the north-west of Wailly. German 88-mm (3.465-in) guns knocked out several Matilda I tanks, but some of the larger Matilda II tanks among the Matilda I vehicles advanced through the artillery and anti-tank fire unscathed, German shells bouncing off their armour. The tanks destroyed the German anti-tank guns with return fire and rolled over them, killing the crews. The British tanks were eventually stopped short of Hill 111 by fire from another artillery battery, but other tanks bypassed the area on both sides. On the 7^th Panzerdivision's southern flank, the SS Division 'Totenkopf' was attacked and some SS troops fled in panic.

The maximum depth of the British advance was 10 miles (16 km), Sone 400 Germans had been taken prisoner, and many tanks and much equipment had been destroyed, but two Matilda II tanks had been knocked out. Only 26 Matilda I tanks were still operational and both tank battalion commanders had been killed. During the evening, Franklyn ordered both columns to withdraw. French cavalry remained near Warlus, but was surrounded during the night and only a few tanks managed to break out. The infantry of the Right Column in Warlus was rescued, because six French tanks arrived with two armoured infantry vehicles and broke out through the German position on the road linking Warlus and Duisans. The garrison in Duisans also retired after the fall of night in the Bren carriers of the 9/DLI, covered by the anti-tank guns of the brigade reserve in Maroeuil. The Left Column troops in Agny and Beaurains were bombed and then came under attack by tanks as they retreated, one party missing the road and eventually reaching Boulogne. The 7^th Panzerdivision laagered overnight south of Dainville, with advanced parties of infantry close to the southern bank of the Scarpe river.

The ground between Arras and the Cojeul river was reoccupied by the Germans and there was no serious German attack on the town, Rommel making the alarmist claim that the attack had been delivered by five divisions. Beyond the delay imposed on German moves and the many casualties inflicted on the Germans, the attack was bound to fail without a force sufficiently powerful to follow and consolidate the captured ground. von Rundstedt had intended that the Panzer divisions should rest after the exertions on 20 May. A proposed attack to the south-west was rejected and the Oberkommando des Heeres ordered the Panzergruppe 'von Kleist' to capture Boulogne and Calais, about 50 miles (80 km) away. Apprehension of another Allied attack caused von Rundstedt to order General Hermann Hoth’s Panzergruppe 'Hoth' (otherwise the XV Corps (mot.)) to remain in position, General Georg-Hans Reinhardt’s XLI Corps (mot.) sent a division to the east as a precautionary measure, and von Kleist diverted the 10^th Panzerdivision and parts of the 1^st Panzerdivision and the 2^nd Panzerdivision from General Heinz Guderian’s XIX Corps (mot.) to hold the bridgehead over the Somme river, which slowed the advance to Dunkirk. The XIX Corps (mot.) attacked again at 08.00 on 22 May, but was still hampered by the German higher command’s near paralysis, von Rundstedt ordering that the instructions from the Oberkommando des Heeres be ignored and that the advance on Boulogne and Calais would have to wait. At 12.40, von Rundstedt countermanded his own order but for five hours, the German armour had waited on the Amache river.

It has been argued that Allied planning was notable for its failure to cut the 'Panzer corridor' when there were insufficient German motorised divisions to consolidate behind the Panzer divisions and the non-motorised divisions were several days' march farther to the rear. The corridor was only 25 miles (40 km) wide at Arras and vulnerable to attack by a pincer movement; The Allies could have achieved a counter-encirclement and cut off the German armour on the English Channel coast. Generaloberst Franz Halder, the Oberkommando des Heeres’s chief-of-staff, had been willing to run the risk because of the incapacity of the Allies to achieve a fast tempo of operations. The Allied attack was contained because Rommel improvised a gun line of anti-tank guns and anti-aircraft guns that managed to stop some of the lighter British tanks. The infantry tanks, especially the Matilda II machines, proved very difficult to halt with the standard 37-mm anti tank gun.

Rommel also used radio to order the rapid establishment of another gun line with artillery and several 88-mm (3.465-in) guns somewhat farther to the rear, and this destroyed 24 tanks in a few minutes on the flat terrain between Mercatel and Tilloy. Just after 18.00. Ju 87 dive-bombers of the I Fliegerkorps and VIII Fliegerkorps arrived to deliver 300 attacks on the retiring tanks by 20.30. Rommel ordered the 25^th Panzerregiment to return and cut off the British tanks, but to the south of Duisans the regiment met French tanks covering the British right flank and pushed through only after a long and costly engagement. When the German tanks had broken through a British anti-tank gun line, between Duisans and Warlus, the British tanks had already returned, and the British attack had turned into a disaster with only 28 of the originally committed 88 tanks returning to their start line. The 6^th Panzerdivision signalled that 'a strong enemy force was making a breakthrough', which caused alarm at the headquarters of the Panzergruppe 'von Kleist'. von Kleist ordered the 6^th Panzerdivision and 8^th Panzerdivision to the east in order to counter the Allied breakthrough. In the aftermath the Germans came to treat the 'Battle of Arras' as a minor Allied defeat.

Rommel noted in his diary that in the 'Battle of Arras' his division had lost 89 men killed, 116 wounded and 173 men missing or taken prisoner, a total as great as that for the first four days of operations, which included the Meuse river crossing, although 90 of the missing laster made their way back to the formation. The 7^th Panzerdivision's war diary recorded the loss of nine medium and several light tanks, 378 men killed or wounded and 173 missing. British records noted some 400 Germans taken prisoner. The British had lost some 100 men killed or wounded. It is unknown how many French soldiers became casualties in the battle. Frankforce lost 60 of its 88 tanks in the attack.

The main French attack on Cambrai took place on 22 May and, as in the attack on 21 May, the force involved was much smaller than intended. The 10ème Armée’s commander, Général de Corps d’Armée Robert Altmayer, should have attacked with the V Corps and tanks of Corps de Cavalerie, but only one infantry regiment and two depleted tank battalions could be assembled in time. The Panzer divisions had moved forward leaving only small detachments in Cambrai and the marching infantry divisions were not due until later in the day. The French attack reached the fringe of Cambrai only to be stopped by the Luftwaffe and forced to retreat.

It has been suggested that the Franco-British counterattack at Arras had a disproportionate effect on the Germans because the latter’s higher commanders were apprehensive about flank security. von Kleist perceived a 'serious threat' and informed Halder that he had to wait until the crisis had been resolved before continuing his force’s advance. von Kluge ordered the tanks to halt, and in this was supported by von Rundstedt. On 22 May, when the attack had been repulsed, von Rundstedt ordered that the situation at Arras must be restored before the Panzergruppe 'von Kleist' moved on Boulogne and Calais. At the Oberkommando der Wehrmacht, the panic was worse and Hitler contacted Heeresgruppe 'A' on 22 May to order that all mobile units were to operate on each side of Arras and infantry units were to operate to the east.

The crisis among the German army’s higher echelons was not apparent at the front, and Halder formed the same conclusion as Guderian that the real threat was that the Allies would retreat to the English Channel coast too quickly, and a race for the English Channel ports therefore began. Guderian ordered the 2^nd Panzerdivision to capture Boulogne, the 1^st Panzerdivision to take Calais and the 10^th Panzerdivision to seize Dunkirk. Most of the British Expeditionary Force and the French 1ème Armée were still some 60 miles (100 km) from the coast but, despite delays, British troops were sent from England to Boulogne and Calais just in time to forestall the XIX Corps (mot.)'s Panzer divisions on 22 May. Had the Panzer formations and units advanced at the same speed on 21 May as they had on 20 May, before the halt order stopped their advance for 24 hours, Boulogne and Calais would probably have fallen. Without a halt at Montcornet on 15 May and the second halt on 21 May after the 'Battle of Arras', the final halt order of 24 May would have been irrelevant, because Dunkirk would have already been captured by the 10^th Panzerdivision.