The 'Battle of the Gembloux Gap' was fought between German and French forces during the German invasion of Belgium in the early stages of 'Gelb' (14/15 May 1940).

When on 10 May the Germans launched 'Gelb' as their invasion of the Netherlands, Belgium, Luxembourg and north-eastern France, the Allies responded with their 'Dyle Plan (Breda variant)', which was intended to halt the German drive into Belgium as what the Allies believed was the primary German offensive. The Allies therefore committed their best and most mobile formations to an advance into Belgium on 10 May, and two days later the Germans began the second part of 'Gelb' as the real primary 'Sichelschnitt' undertaking. This was an advance through the 'impenetrable' Ardennes region, reach the Somme river in the Sedan area, break though and drive to the southern coast of the English Channel and thereby cut off the Allied forces in Belgium.

Unaware that the German penetration into the Low Countries was little more than a decoy, the French army intended to halt the German advance into central Belgium and north-eastern France on two defensive positions at the towns of Hannut and Gembloux. Général d’Armée Georges Maurice Jean Blanchard’s 1ère Armée, the most powerful Allied army, was to defend the axis from Wavre to Gembloux. Général de Corps d’Armée René Prioux’s Corps de Cavalerie advanced to Hannut, to screen the deployment of the rest of the 1ère Armée at Gembloux, by delaying a German advance.

After the 'Battle of Hannut', some 22 miles (35 km) to the north-east, the French retired toward Gembloux and the principal defensive position for the French on the Belgian front. For two days French defeated attacks by elements of Generaloberst Walter von Reichenau’s 6^th Army. the 'Sichelschnitt' attack through the Ardennes and the crossing of the Meuse river at Sedan forced the 1ère Armée to retreat from Gembloux, then back over the French frontier toward Lille. The retreat disorganised the Allied defence of the central sector of the Belgian front and the German armies occupied central Belgium. Strategically the battle was inconclusive: it diverted the 1ère Armée from Sedan, which allowed the Germans to achieve the strategic goals of 'Gelb', but the 1ère Armée survived and during the 'Siege of Lille' forced the diversion of German forces from the 'Battle of Dunkirk', which allowed General the Lord Gort’s British Expeditionary Force and a substantial French contingent to escape in 'Dynamo'.

Between industrial north-eastern France and Paris and the industrial region of the Rhine-Ruhr river basin of Germany, the plain of central Belgium was a natural route of invasion. A ridge running approximately north-east/south-west through the Gembloux area forms a watershed: to the west, streams flow into the Escaut (Scheldt) river and to the east into the Meuse (Maas) river, and possessing few if any natural obstacles the area is known as the Gembloux gap (Trouée de Gembloux in French).

The strategy, operational methods and tactics of the German army and air force are often labelled Blitzkrieg (lightning war). The concept is controversial and is connected to the problem of the nature and origin of Blitzkrieg operations, of which the 1940 campaign is often described as a classic example. An essential element of Blitzkrieg was considered to be a strategic, or series of operational developments, undertaken by mechanised forces to cause the collapse of the defenders' armed forces. Blitzkrieg is also regarded as a revolutionary form of warfare, but its real novelty and its existence have been disputed. Rapid and decisive victories had been desired and planned well before World War II. In the German wars of unification and World War I campaigns, the German general staff had attempted Bewegungskrieg (war of manoeuvre), similar to the modern perception of Blitzkrieg, with varying degrees of success. During World War I, these methods had achieved tactical success, but operational exploitation was slow as armies had to march on foot anywhere beyond their railheads. The use of tanks, motorised infantry and artillery, and aircraft enabled the Germans to attempt Bewegungskrieg in 1940 at a tempo considerably greater than that of the slow-moving armies of World War I. The internal combustion engine and radio communication solved the problem of operational-level exploitation.

The term Blitzkrieg is seen as an anomaly as there was no explicit reference to such strategy, operations or tactics in German battle plans. There is no evidence in German strategic, military or industrial preparations implying the existence of a formally schemed Blitzkrieg concept. Evidence suggests that in 1939 and 1940 Germany was preparing its economy for a war of attrition, not a quick war of manoeuvre, although there was no total economic mobilisation for the war. Adolf Hitler’s miscalculations in 1939 forced him into war before the war economy was ready and under these circumstances, the German general staff reverted to the Vernichtungsgedanke, attempting to win a war quickly, with swift attacks on the flanks and rear of opposing armies, leading to their destruction before the economic and matériel superiority of the Allies became overwhelming. It was only after the defeat of France in 1940 that the German military intentionally pursued a Blitzkrieg type of warfare in its efforts to achieve Hitler’s ambitions in Europe.

French military doctrine resulted from the nation’s experiences in World War I. With only half the population and one-third of the industry of Germany, France had suffered proportionally a much higher loss, especially in those killed or permanently disabled. French doctrine therefore rested on the idea of a battle carefully controlled by senior commanders to reduce losses. Doctrine relied on defence in depth, keeping mobile forces away from the opponent’s fire and to secure the line against incursions of the opponent’s armour. The defence of the infantry division on open terrain was based on the light and medium artillery for direct support of the infantry and tanks, and heavier pieces were reserved for use by the senior commander to make his personal intervention felt on the battlefield. Infantry was to be disposed in depth: from 15 to 30% of a division’s infantry strength was to be disposed in outposts on commanding ground before the main position to cover it from surprises, then the main position of resistance along a natural or artificial terrain obstacle covered by the general barrage of infantry and anti-tank weapons in a position 1.25 miles (2 km) deep down to a stop-line where an anti-tank screen was to be located. Units were to be emplaced on commanding terrain in closed positions capable of defence in all directions, covering the intervals between them with cross fire. Behind the stop-line would be reserves, the divisional reconnaissance battalion and the artillery battery positions in closed strong points. Defence against tanks was a priority throughout the depth of the position. A division on open terrain would hold a front 3.7 to 4.3 miles (6 to 7 km) in width and some 3.1 miles (5 km) in depth.

The high command held back in reserve battalions of infantry-support tanks for key infantry formations. Leading elements of the French army trained to respond to the armoured and air threat, including those under Général de Corps d’Armée Henri Marie Joseph Aymes, commander of the IV Corps which fought in the 'Battle of the Gembloux Gap'. French doctrine provided for air reconnaissance and observation, fighter defence of ground forces and on occasion bomber support, although this principle was not always available in practice: the French forces of 1940 were far better supplied with artillery than aircraft, and thus reality frequently overtook doctrine.

The German strategy in 'Gelb' required the 6^th Army to drive its mechanised and motorised formations into the Belgian plain and strike at Gembloux, defeating or pinning Allied forces, while the main German effort was made through the Ardennes to the Meuse river and the 'Battle of Sedan' in order to cut off the Allied forces in Belgium and northern France. von Reichenau expected Allied motorised forces in the area of the Dyle river and Namur from the second day of operations, with troops brought up by railway from the fourth day. He chose to concentrate his attack between Wavre and Namur where prepared defences seemed the weakest. Luftwaffe medium bombers were to hinder the advance of the Allied forces into Belgium.

The French command was sure that the Germans would have as their Schwerpunkt (point of main effort) on the Belgian plain and Grand Quartier Général (French high command) planned to defeat the German move with the 1ère Armée, the British Expeditionary Force and Général d’Armée Henri Honoré Giraud’s 7ème Armée, which contained the majority of the Allied mechanised and motorised troops. The 'Dyle Plan (Breda variant)' was designed to push the Allied advance into Belgium to defeat the German offensive. French doctrine opposed an encounter battle with an opponent possessing air superiority, and the high command was unwilling to invest more than a limited quantity of French manpower in what was likely to prove a bloody battle.

Commanded by Blanchard, the 1ère Armée was allocated the critical mission of holding the Gembloux gap. Blanchard’s army would therefore have to advance some 60 miles (100 km) from the Franco/Belgian frontier. In the process, its front would shrink from some 60 miles (100 km) to 18.4 miles (30 km) in the Gembloux gap, where the Belgian army was to prepare defences for it. Prioux’s powerful Corps de Cavalerie, generally equivalent to a Panzer corps, was to cover the deployment of the 1ère Armée as it narrowed its front and was vulnerable to attacks by the Luftwaffe. The high command allotted Blanchard conventional infantry installed on the frontier as well as advance formations of motorised infantry divisions and the 1ère Division Cuirassée (heavy armoured division), including some 70 heavy tanks.

Blanchard received no more than one-third of the anti-aircraft weapons he requested, and thus opted to move his troops only at night. This meant that he would require at least eight days to dig in his infantry divisions, only three of which were motorised, before the Panzers arrived, or it would be an encounter battle delivered under the worst conditions.

Général d’Armée Gaston Billotte, commander of the 1er Groupe d’Armées to which the 1ère Armée belonged, insisted that the 1ère Armée have a force of powerful armour with which to guarantee that it could and would the Gembloux gap. Billotte wished to have two divisions cuirassées operating under an armoured corps, with the 1ère Division Cuirassée ready for action by the sixth day of operations. He laid down three axes of counterattack and also warned that German tanks might attack from the sixth day of operations (in fact they attacked one day earlier) but Général d’Armée Alphonse Joseph Georges, commander of the North-Eastern Front and Billotte’s superior, refused to commit the 2ème Division Cuirassée in advance. The 1ère Division Cuirassée was ready for action by the morning of 14 May, the fifth day of operations. The Allies also agreed that the British Expeditionary Force would move forward between the 1ère Armée and the Belgian army, to a front along the Dyle river; the British planned to move by both day and night.

An important consideration in the Allied plan was the assurance that the Belgian army would prepare defences in the Gembloux gap in the centre of the Dyle position. The first trace of this Belgian position used the railway line linking Namur and Brussels as a tank obstacle, in accordance with French intentions. As the German invasion was repeatedly postponed, the Belgian command revised the trace eastwards in the hope of drawing the French closer to the German/Belgian frontier, and on 10 May there was only a partial anti-tank obstacle to the east of the 'Dyle Line'. Around Gembloux there were almost no defences: French intelligence was at least partially aware of this, but the French were taken by surprise by the lack of field fortifications they found on 10 May.

On the German side and forming part of Generaloberst Fedor von Bock’s Heeresgruppe 'B' was von Reichenau’s 6^th Army. Its forces at Gembloux were mostly first-line troops and experienced reservists: these formations had been active divisions before the start of the war and had been fleshed out with reservists as war approached, had the best equipment establishments in the German army, and most had seen action on the 'Weiss' (i) invasion of Poland the preceding September. The army’s formations included the General Erich Hoepner’s XVI Corps (mot.) and General Viktor von Schwedler’s IV Corps.

It was Hoepner’s XVI Corps (mot.) which spearheaded the attack at Gembloux. Its forces included Generalleutnant Horst Stumpff’s 3^rd Panzerdivision, which on 10 May had the 3^rd Panzerbrigade with 343 tanks, the infantry of the 3^rd Schützenbrigade, one artillery regiment and one squadron of reconnaissance aircraft, plus engineer and service personnel. Of its 343 armoured fighting vehicles, only 42 were medium tanks: 16 PzKpfw III medium tanks and 26 heavier PzKpfw IV battle tanks). Generalmajor Johann Stever’s 4^th Panzerdivision had the 5^th Panzerbrigade with 331 tanks, the 4^th Schützenbrigade two artillery regiments and support forces like those of the 3^rd Panzerdivision. Of its 331 armoured fighting vehicles, only 20 were PzKpfw III medium tanks and 24 were PzKpfw IV battle tanks. Hoepner also disposed of Generalleutnant Mauritz von Wiktorin’s 20^th Division (mot.) and Generalleutnant Hans Wolfgang Reinhard’s 35^th Division during the 'Battle of the Gembloux Gap'.

To the right of Hoepner’s XVI Corps (mot.), Schwedler’s IV Corps had, from north to south, Generalleutnant Rudolf Kämpfe’s 31^st Division, Generalleutnant Eccard Freiherr von Gablenz’s 7^th Division and Generalleutnant Friedrich-Karl Cranz’s 18^th Division. The infantry divisions′ artillery and transport units were generally reliant on horse power, and each of the divisions was therefore much slower than the Panzer and motorised divisions. During the course of the first day, Generalleutnant Ernst-Eberhard Hell’s 269^th Division of General Werner Kienitz’s XVII Corps arrived, as did von Wiktorin’s 20^th Division (mot.), which was used as flank protection to the south on the road linking Gembloux and Namur.

The Germans placed great reliance on the Luftwaffe to provide air superiority. Like the French command, the German high command had planned a joint air/land battle, but unlike the Allied air forces, the Luftwaffe had the operational strength, techniques and training to make the idea work. General Albert Kesselring’s Luftflotte II supported Heeresgruppe 'B', and its strength on 10 May included some 170 twin-engined medium bombers and about 550 single-engined standard and twin-engined heavy fighters, although not all of these numbers were active during the first days of 'Gelb'. The Oberkommando der Luftwaffe reinforced Luftflotte II in the morning of 15 May with General Ulrich Grauert’s I Fliegerkorps from General Hugo Sperrle’s Luftflotte III, which had some 300 medium bombers on 10 May. Most importsantly of all, Generalmajor Wolfram Freiherr von Richthofen’s VIII Fliegerkorps, which had some 300 Junkers Ju 87 single-engined dive-bombers on strength on 10 May and specialised in ground-support operations, supported Hoepner in the 'Battle of the Gembloux Gap'.

The 'Battle of the Gembloux Gap' was fought on the French side by Blanchard’s 1ère Armée, part of Billotte’s 1er Groupe d’Armées. The major units which fought at Gembloux were comparable with the German reservist divisions. The 1ère Armée contingent at Gembloux had Prioux’s Corps de Cavalerie, comprising mainly the 2ème and 3ère Divisions Légères Mécaniques (light mechanised divisions) which had preceded the rest into Belgium, and the III, IV and V Corps d’Armée each with one motorised infantry division and one division d’infanterie nord-africaine (North African infantry division) or division marocaine (Moroccan division). Four 'fleets' of trucks and buses were allotted to the 1ère Armée for the movement of all its motorised infantry and support its conventional units. The French North African and Moroccan formations were high-grade forces of the peacetime army, serving overseas, better paid and attracting the most experienced officers from the service schools.

French infantry divisions each comprised three regiments each of three battalions, two regiments of artillery, one cavalry reconnaissance battalion and an assortment of service troops. Armament included modern mortars, 52 25-mm Hotchkiss anti-tank guns and six to eight 47-mm APX anti-tank guns, Canon de 75 M (montagne) modèle 1928 and Canon de 155mm GPF pieces of field artillery dating from World War I. In selected divisions, one group of 12 155-mm (6.1-in) guns was replaced by 12 modern Canon de 105 court modèle 1935 B guns. Motorised infantry divisions had a cavalry battalion with armoured cars. The infantry support tank battalion involved in the 'Battle of the Gembloux Gap' was equipped with 45 Renault R35 machines: although slow, manned by two reservists, lacking radio and armed with a 37-mm AC 37 low-velocity anti-tank gun of limited effect in the anti-tank role, the Renault was nonetheless powerfully armoured for its time and made a small target. The French infantry divisions which fought at Gembloux also had light automatic anti-aircraft weapons.

Morale in the 1ère Armée’s formations and units was high, based on the soldiers' confidence in their equipment and their leaders. Général de Corps d’Armée de Fornel de La Laurencie’s III Corps d’Armée and especially Aymes’s IV Corps d’Armée played the critical roles in the 'Battle of the Gembloux Gap'.

From north to south, the III Corps d’Armée comprised the 2ème Division d’Infanterie Nord-Africaine and the 1ère Division d’Infanterie Motorisée (motorised infantry division). Both were complete in personnel and matériel. The 2ème Division d’Infanterie Nord-Africaine had battlefield experience from the small-scale 'Saar' offensive of September 1939, while the 1ère Division d’Infanterie Motorisée was unblooded. About half of its cadres were reservists.

From north to south, the IV Corps d’Armée comprised the 1ère Division Marocaine and the 15ème Division d’Infanterie Motorisée. More than the rest, Général de Brigade Albert Raymond Mellier’s 1ère Division Marocaine bore the brunt of the Panzer attack at Gembloux: heir to the prestige of the 1ère Division Marocaine of World War I, the formation comprised mostly Moroccan regulars supplemented by European reservists. The 2ème Régiment de Tirailleurs Marocaines, for example, had 2,357 men present at Gembloux, several hundred having been caught on leave by the sudden German offensive. Of those present, 925 were Europeans and the other 1,432 Moroccans. French cadres were both of active and reservist personnel. A few Moroccans had risen to be junior officers and the non-commissioned officer cadre was mixed: in the light artillery the officers were all French and mostly active duty, and in the heavy artillery all officers were French and most were reservists. Mellier had been their commander since the end of February. He was known to be extremely active and spoke perfect Arabic. However, the Moroccans had the reputation of being better in the attack than in the defence. Despite the fateful mission which awaited it, the Division Marocaine had only 27 25-mm anti-tank guns among its infantry rather than the 48 such weapons that were on its established strength. There were anti-aircraft weapons with the regiments but no divisional battery, and the divisional transport lacked vehicles and some 400 horses. In support of the Division Marocaine was Général de Brigade Alphonse Pierre Juin’s 15ème Division d’Infanterie Motorisée. Juin had the 'absolute confidence' of his men in a unit complete in personnel and armed to the highest standards of the French army of the time, and the 15ème Division d’Infanterie Motorisée was thus ready to contribute significantly to the defence at Gembloux.

The primary French weakness was in the air. By the time the 'Battle of the Gembloux Gap' began, the 1ère Armée had only the remains of one group of 26 fighters, one reconnaissance group and the observation squadrons.

The Corps de Cavalerie had defeated German attempts to close on the 'Dyle Line' in the 'Battle of Hannut' and retired to the second line of defence at Gembloux, about 22 miles (35 km) to the south-west. The French and German tanks had exacted a heavy toll on each other, the French having knocked out 160 German tanks for the loss of 105 of their own vehicles. By retreating from the battlefield, the French lost many of their knocked-out tanks, while the Germans were able to recover and repair almost three-quarters of their disabled vehicles: only 49 tanks were destroyed and 111 tanks were repaired. German casualties were 60 men killed and another 80 wounded.

Hoepner pursued the French despite warnings from the 35^th Panzerbrigade of Stever’s 4^th Panzerdivision that its losses at Hannut meant any further damage would be tantamount to 'suicide'. Hoepner did not wait for the infantry divisions to close up and tried to bounce the French out of their defences. The XVI Corps (mot.) ran into retreating French columns and inflicted many losses. The closeness of the pursuit created severe problems for the French artillery, which was reluctant to risk inflicting casualties on its own side. The French established new anti-tank screens and, lacking infantry support, Hoepner was forced into a frontal attack. His two Panzer divisions reported many losses on 14 May and were forced to slow their pursuit. During the aftermath, the French armoured units were joined by fresh formations and units, which then set up a new defensive position to the east of Gembloux.

The Panzer forces moved out on 14 May to overrun the Dyle river position. Until at least 09.20, air reconnaissance indicated that the position was unoccupied. At that hour, Hoepner was with the 4^th Panzerdivision urging that unit to break through on both sides of Ernage without waiting for Stumpff’s 3^rd Panzerdivision. Generalleutnant Hans Wolfgang Reinhard’s 35^th Division and von Wiktorin’s 20^th Division (mot.) were both behind the Panzer formations, respectively on their right and left flanks. The 4^th Panzerdivision ordered an advance with it armoured and infantry elements operating together. The division’s left flank was to be covered by the reconnaissance battalion, one machine gun battalion and most of one anti-tank battalion. At 11.30, the 8^th Kompanie of the 35^th Panzeregiment attacked from Baudeset with some 30 tanks toward the railway line to the south of Ernage, but was stopped with the loss of nine tanks by French artillery fire and withdrew. The 6^th Kompanie was unable to aid its sister company because of the 'annihilating defensive fire'.

At 13.30, the 4^th Panzerbrigade ran into French positions between the railway line and the road linking Wavre and Gembloux, and the Germans now conceded that the Dyle river position was defended. The action of the 3^rd Panzerdivision on 14 May is less clear. That morning, the 3^rd Panzerbrigade crossed the Belgian anti-tank obstacle behind the 4^th Panzerdivision, with the 5^th Panzerregiment on the right and the 6^th Panzerregiment on the left. Oberst Georg Kühn, the brigade commander, was with 6^th Panzerregiment, which became involved in the fighting in Ernage and on the road linking Wavre and Gembloux, the tanks being taken under 'lively' artillery and anti-tank fire. Kühn decided to await the arrival of infantry support.

While the Panzer formations blundered into the French defence, the 6^th Army pressed its infantry corps forward to cover their flanks. Schwedler’s IV Corps was to cover the Panzers' right flank as it had done against the French cavalry on 13 May at Hannut. The infantry made good progress against virtually no resistance early on 14 May and advance guards of the 31^st Division, 7^th Division and 18^th Division contacted the Dyle position that afternoon and evening. At 21.50, Generalmajor Friedrich Paulus, the 6^th Army's chief-of-staff, urged the infantry forward in support of the 3^rd Panzerdivision, which was involved in heavy fighting at Walhain and Ernage. By the end of 14 May, the divisions reported the Dyle position to be occupied. The corps found demolitions and mining on the approach routes difficult to negotiate. As German forces moved into contact, the 1ère Armée suffered the attentions of the Luftwaffe. French fighters could barely cover the three or so reconnaissance missions flown into the area beginning that morning and in which most of the reconnaissance aircraft were lost. The retreating Corps de Cavalerie establish the main details of the German advance and delayed the Panzers to the north of Ernage near the positions of the 3ème Division Légère Mécanique, and around Grand Leez near the 2ème Division Légère Mécanique. As the cavalry left the field, Blanchard ordered its tanks to remain nearby in reserve. Meanwhile, the German thrust continued to develop to the south.

That evening, Billotte’s headquarters warned the 1ère Armée to prepare for a possible retreat, but the formations in the field knew nothing of this. The 1ère Division d’Infanterie Motorisée was disturbed by the retreat of the cavalry and the flow of Belgian infantry and refugees during the afternoon of 14 May. The first dive-bomber attack made a great impression on the troops, for whom this was their baptism of fire. False rumours of the landing of airborne forces led to brief 'friendly fire' incidents in which several artillerymen were killed. By that evening, de La Laurencie’s III Corps d’Armée and units of the British and Belgian armies on the Dyle position and at Namur made contact with German patrols.

Hoepner was now fully aware that the Dyle position was defended. Nonetheless, until at least 16.50, higher headquarters urged him to pursue the 'defeated' French. To the north, the 3^rd Panzerdivision became locked in fighting on its right flank, as noted above. At 14.00, the XVI Corps (mot.) ordered the 35^th Division to move in that direction, while the 20^th Division (mot.) was to move to the corps' other flank, and the arrival of the 269^th Division from the XVII Corps on the northern edge of the Namur fortress relieved fears from that direction. At 14.05, Stever ordered Oberst Hermann Breith’s 5^th Panzerbrigade, supported by one infantry battalion, to attack on a narrow front to the south of Ernage with the object of reaching the hills to the east of St Gery. The divisional artillery would neutralise flanking fire from Ernage and Gembloux. At 16.00, Stever delayed the attack so that the 3^rd Panzerdivision could prepare. At 16.50, Stumpff radioed the 4^th Panzerdivision that he would inform it when he was ready, but in the meantime began his own attack in the Ernage area alone. After 18.00, the XVI Corps (mot.) again pressed its divisions to attack, but the French defensive artillery barrages were so dense that a poison gas alert was mistakenly declared and stopped these attacks. At 20.50, Hoepner radioed his divisional commanders to halt their offensive until the morning of the following day.

That afternoon, the 4^th Panzerdivision had suffered both from the French defence and German command confusion. Stevers went forward to meet Breith, commanding the 5^th Panzerbrigade and Oberst Hans Freiherr von Boineburg-Lengsfeld, commanding the 4^th Schützenbrigade, who both insisted that a prepared attack was no longer possible that day. French artillery shelled the headquarters of the brigades out of Baudeset, leaving two infantry battalion commanders dead. The bombardment was accurate from the first round, a number of German tanks taking direct hits as they waited around Baudeset. Harassing fire continued all night, forcing crews to dig in under their tanks.

The plan of the 3^rd Panzerdivision for 14 May is unclear. The division’s left-flank unit, the 6^th Panzerregiment, did attack in the Ernage area in the afternoon and was checked by defensive fire. The supporting infantry failed to arrive and the 3^rd Panzerbrigade reported being under French air observation after 19.00. Meanwhile, serious fighting was reported with tanks of the 3ème Division Légère Mécanique in the Walhain-St Paul area, and French tanks also appeared at Ernage, leading the 3^rd Panzerbrigade's command to conclude that the situation was critical. French armour, against which only the 75-mm (2.95-in) gun of the PzKpfw IV battle tank was genuinely effective, was trying to break through both on the left and the right with artillery support directed by spotter aircraft while the German infantry had not yet arrived. This was a misreading of French intentions, but it was indicative of the exaggerated fears suffered by the command of the 3^rd Panzerbrigade. During the night that followed, the front quietened. The German infantry arrived and, driven on by urgent orders issued hours earlier, advanced in the dark. Despite coming under the erroneous fire of their own tanks, one battalion almost reached the French main position, and found itself alone before dawn between Ernage and Perbais with no radio contact with the division.

Hoepner had decided to commit his armour with all available artillery and air support at a solid French defence rather than wait another day to bring up his two infantry divisions for a more powerful effort. Encouraged by his superiors and the thrust of German doctrine to attack before the opponent could further prepare himself, Hoepner decided at about 20.00 on 14 May not to wait. 6^th Army intelligence continued to insist that the Allies were retreating, ordering the XVI Corps (mot.) to pursue and falsely claiming that German armour was already to the west of Gembloux. Nonetheless, at 22.45 the corps ordered an assault by the 3^rd Panzerdivision and 4^th Panzerdivision for 08.00 on 15 May with the railway line on each side of Tilly, well beyond the French defences at Gembloux, as their first objective. The VIII Fliegerkorps and all the artillery available would support the assault on both sides of Ernage on a front of less than 3.7 miles (6 km), and engineer units were to repair the blown bridges and crossroads supposedly left in their wake by the Allied retreat and which threatened to disrupt German logistics.

Stever ordered his 4^th Schützenbrigade to deploy three battalions in line from Gembloux to Ernage, echeloned back on their left flank. In addition to air support, one artillery regiment would fire a 30-minute preparation on the French main position, then fire smoke shell to blanket Gembloux, after which both of the division’s artillery regiments and one heavy artillery battalion would concentrate on counter-battery fire and areas impenetrable to armour. Anti-aircraft guns would neutralise the French bunkers, of which there were in fact none. As the infantry crossed the railway line they were to fire white flares. At this signal, Breith’s 5^th Panzerbrigade was to break cover and charge the French position together with the infantry. Pursuit in the direction of Nivelles would follow. Stumpff’s plan for his 3^rd Panzerdivision is less clear. He too put his infantry ahead of the armour with dive-bomber and artillery support, ordering a few tank units to support the infantry. His first objective was to reach two hills to the west of the line between Chastre and Noirmont. The mass of the German armour would wait in reserve to deal with French armour or to exploit the breakthrough.

To the Panzer divisions' right, the IV Corps was to engage in bitter fighting in the morning of 15 May and at 09.20 warned its divisions that a 'decisive battle' was developing along the Dyle river. The corps ordered a concentrated effort in the Ottignies area at the boundary between the 7^th Division and 18^th Division. An exploitation group would follow up the expected breakthrough. Meanwhile, the Luftwaffe reinforced Luftflotte II, many of whose units had by now lost between 30 and 50% of their strengths, with the I Fliegerkorps from Luftflotte III. In effect, the high command gave priority to the 6^th Army in its effort to defeat the Allied forces.

The day was hot and clear. French artillery had fired heavily all night, but the planned dive-bomber attacks and German artillery preparation proceeded from 07.30. Some 30 minutes later, the infantry of 4^th Panzerdivision advanced undisturbed by French shelling. At 08.10, the German infantry fired white flares indicating that they had crossed the railway line, but at 08.20 French artillery engaged the incursion and as they drove forward, the German tanks were pinned down. At 09.30, Oberst Curt von Jesser’s 36^th Panzerregiment was suffering heavy losses while at a standstill in front of the obstacle, Oberst Heinrich Eberbach’s 35^th Panzerregiment facing the same situation from 09.45. When the 5^th Panzerbrigade's headquarters asked why the infantry was not advancing, the reply was 'attack hopeless'. By 10.00, the 2/12^th Infanterieregiment had a company on the railway line at Gembloux, but the advance was slow and costly and had come to a halt by 11.00. Radio contact with the 5^th Panzerbrigade was lost and the tanks were milling around before the obstacle and being picked off individually.

Meanwhile, infantry of the 3^rd Panzerdivision attacked from Walhain-St Paul against Perbais at 09.15, but they too had been brought to a halt by 11.00. The war diarist of the XVI Corps (mot.) complained that the tanks of the 4^th Panzerbrigade had joined the fray before the anti-tank obstacle had been cleared. The corps' operations officer, Oberst Walter Chales de Beaulieu, an officer of French descent, criticised the 3^rd Panzerdivision for allowing its infantry to bog down while leaving its tanks in reserve.

The dive-bombers and artillery failed to silence the French artillery: most of the reports of French batteries were too imprecise to be of use, and tactical reconnaissance aircraft were hindered by French fighters. At 10.30, the heavy artillery battalion had itself to flee French counter-battery fire. By 11.18, the weight of French shelling on approach routes and installations drove the corps artillery commander to conclude that efforts to hold gains and bring in reinforcements were 'gravely threatened'. One German source reported that the assault was stuck fast on the road between Wavre and Gembloux, with only one battalion at first reaching the railway, followed immediately by a French tank and infantry counterattack against which German anti-tank guns had little effect. The crews of some of the German anti-tank guns fled without even opening fire. However, there is no known French record of French tanks on the field at this point in the battle.

Breith led his 5^th Panzerbrigade in his command tank, which was forward with the 35^th Panzerregiment. Seeing his attack bog down, Breith had some of his officers leave their machines to rally the infantry to attack the anti-tank guns. His own crew could see anti-tank mines lying unburied on the ground. Some of the French and Moroccans surrendered. An infantry support gun arrived and added its fire. Breith’s command vehicle then took two hits, although it was not penetrated. The tank began to move toward Ernage when it was again hit, Breith being slightly wounded and his crew bailing out. A light tank which tried to rescue them was in turn hit and its crew had to seek shelter in shell holes. A Hauptmann von Jungenfeld was not far from them and noted that as they reached the railway line all the heavy vehicles of the 4^th Kompanie were destroyed, the tank of Eberbach, the regimental commander, being knocked out. Eberbach told his subordinates that 'further advance is simply impossible. Our tanks sit and before the obstacles the defence fire strikes us mercilessly.'

When the tanks finally began to fall back, the 1/12^th Infanterieregiment also withdrew, contrary to orders, forcing staff officers to turn out to stem the retreat. An attempt by 36^th Panzerregiment to exploit a gap in the railway embankment near Lonzee against the 15ème Division d’Infanterie Motorisée broke down immediately under French fire. The 4^th Panzerdivision had been halted.

Since the 3^rd Panzerdivision withheld its tank brigade, its battle proceeded somewhat differently. At dawn on 15 May, the 3/3^rd Infanterieregiment was located to the north-east of Ernage, but its 1/3^rd Infanterieregiment and 2/3^rd Infanterieregiment, to the north and north-west of Ernage respectively, had moved too far to their right during the night, thus opening a gap of 0.6 and 1.2 miles (1 and 2 km) between the 3^rd Panzerdivision and 4^th Panzerdivision, which should have abutted each other near Ernage. Thus, the 3^rd Panzerdivision found itself engaged more against the 110ème Régiment d’Infanterie of the 1ème Division d’Infanterie Motorisée at Perbais than intended. At dawn, German warplanes and artillery deluged Ernage. The 1/3^rd Infanterieregiment attacked the northern edge of the village, but its attack broke down under infantry fire. At 08.00, after additional air and artillery preparation, the 2/3^rd Infanterieregiment, hampered by its own artillery which was firing 'blind' on the basis of map co-ordinates, advanced toward Perbais and also failed. The commanders of the two battalions met to co-ordinate their efforts, while the 3/3^rd Infanterieregiment, to the west of Baudeset, received orders to close the gap between the 3^rd Panzerdivision and 4^th Panzerdivision.

In a second effort, the 1/3^rd Infanterieregiment and 2/3^rd Infanterieregiment renewed their advance with the support of Oberst Kurt Forster’s 75^th Artillerieregiment, which on this occasion provided observed fire to better effect. Profiting from this and a dive-bomber attack, the infantry took Perbais despite suffering heavy losses to French artillery fire, and advanced to the railway line. A few tanks arrived in support, and the German situation began to look more promising.

On the whole, however, it had been a bad morning for the XVI Corps (mot.). On the French side of the plain, however, the Luftwaffe’s intense effort made a powerful impression. Against them, the Armée de l’Air had furnished only two fighter sweeps. Reconnaissance aircraft sent by the 1ère Armée and IV Corps d’Armée fell victim to Flak and German fighters, and command of the air was firmly in German hands. The IV Corps d’Armée bore the brunt of the Panzer assault. From dawn, ground observers reported some 300 German tanks approaching French lines, Aymes claiming that German attacks began at about 06.00, were checked, then followed from 08.00 by waves of dive-bombers which attacked the whole depth of the position. The Germans crossed the railway in the sector of the 2ème Régiment de Tirailleurs Marocaines, and reports reached corps headquarters that Perbais and Chastre, in the zone of the 1ère Division d’Infanterie Motorisée, had fallen, threatening the IV Corps' left flank. Aymes released one infantry support tank battalion to each of his divisions and gave his corps reserve infantry battalion to the Division Marocaine. To handle the situation behind Perbais, Aymes wished the tank brigade of the 3ème Division Légère Mécanique to counterattack, but the division’s commander, Général de Brigade Pierre de La Font, told him that de La Laurencie of the III Corps had already taken control of the armour without informing Aymes.

The Division Marocaine withstood the assault of roughly one and one-third Panzer divisions. The 7ème Régiment Marocaine in Ernage, like the neighbouring 110^th Régiment in Perbais, fought bitterly before giving ground. The mixed post between the two regiments was encircled but maintained its resistance until 15.00. The 2ème Régiment Marocaine was on exposed terrain, and by 12.00 seven platoons on its front had been all but destroyed, although support elements held on. The 1ère Régiment Marocain in Gembloux was driven back into the town but then held, although the Germans succeeded in infiltrating to the west of the town along the railway linking Gembloux and Nivelles, parallel with the Chaussée Brunehaut highway. German bombing caused losses and some panic among the artillery, however, and the infantry battalions at the front felt a lessening of their fire support.

Roaming his front on a motorcycle, Mellier judged that his centre was sound and his right at Gembloux strong, but he had to deal with the threats at Ernage and along the railway linking Gembloux and Nivelles. He decided to re-establish contact with the 1ère Division d’Infanterie Mechanisée on the stop-line near Cortil-Noirmont, then to retake the main position using the corps reserve (3/7ème Régiment Marocaine) and one tank brigade of the 3ème Division Légère Mécanique. To re-establish his right and centre, Mellier decided to commit the divisional reserve (3/2ème Régiment Marocaine) and one tank battalion.

French artillery played a critical role in the battle. During the previous night, the batteries of 75-mm (2.95-in) guns posted forward in the anti-tank role had returned to their battalions, possibly on the assumption that the tank threat was now less pressing than that of the German infantry. From a time early in the morning, dive-bombers concentrated on the artillery of the Division Marocaine. Two batteries had their guns overturned, although they later returned to action. There was panic in a reservist battalion from the general reserves; one battalion of 105-mm (4.13-in) guns from the corps artillery which had not yet been integrated into the fire plan suffered casualties and its commander pressed for a fire mission to shore up his men’s morale. Pointed at the Bois de Buis, as likely cover for German tanks, the 105-mm (4.13-in) guns fired at maximum rate, provoking heavy air attack by dive-bomber units. The artillery of the Division Marocaine had clearly lost some of its effectiveness, but this was ot the case of the 15ème Division d’Infanterie Motorisée, whose flanking fire greatly aided the Division Marocaine, which did not suffer many casualties.

The French infantry and support weapons were hard hit, and losses among the junior officers, whose leadership was critical to the capabilities of colonial troops, were particularly heavy. The 1/2ème Régiment Marocaine had two companies on the railway line: Lieutenant Grudler, commanding the 2ème Companie, was killed, reservist Capitaine Bouvier was wounded and captured toward 13.30 after being attacked by a battalion supported by some 30 tanks and 20 aircraft, and two company commanders of the 1ère Régiment Marocaine were killed. The 1/7ème Régiment Marocaine had two companies forward of the railway at Ernage: that of Lieutenant Jouval in the south of the village was encircled by infiltrators by 06.30, and that to the north was outflanked by tanks of the 3^rd Panzerdivision and infantry, and was also hit by effective artillery fire. Finally the battalion commander ordered a withdrawal to the railway line, leaving Jouval to fight on alone. Dive-bomber attacks initially made a great impression on the troops but, according to Lieutenant Goubard, executive officer of the 2ème Régiment Marocaine, the troops quickly learned to move in a dispersed pattern and to take cover only when actually attacked. The French anti-aircraft and automatic weapons also took a toll of their attackers.

By this time, ammunition was running short among the French forces, and therefore their rate of fire declined. This encouraged some of the German tanks to slip around theFrench flank behind a hedge, but the movement was spotted and seven tanks were destroyed. The neighbouring 110ème Régiment coped with the northern wing of the Panzer attack. From 05.00, the divisional reconnaissance battalion retreated onto its 1ère Bataillon, which felt the full weight of the German bombardment and the subsequent infiltration of infantry into Ernage, exposing the battalion’s right flank. The 31ème Bataillon to the north was also forced back. Despite the support of all the divisional anti-tank weapons still available and then the divisional reserve battalion, the 110ème Régiment’s front remained vulnerable.

Meanwhile, the IV Corps fought a parallel battle to the north-west. Attempts to infiltrate across the Dyle river failed and the infantry divisions had to organise set-piece attacks which drove the French outposts back to Ottignies at about 10.00. The 7^th Division prepared an attack on Limal, while the 31^st Division had to regroup before engaging the British to the north of Wavre. The III Corps d’Armée thus found itself in heavy fighting during the morning of 15 May, although only its right-hand 110ème Régiment faced German armour. The artillery of the 2ème Division d’Infanterie Nord-Africaine could not completely check the German infiltrations, and by 12.00 the defenders had retreated to Ottignies.

Hoepner arranged for a fresh dive-bomber attack to be delivered at 12.00 and ordered his divisions to exploit this in order to break through the French position. The French fire did not decline, however, and at 12.30 Eberbach, commander of the 35^th Panzerregiment, refused to renew the attack, having lost half his tanks including his own. Stever came up to the headquarters of the 33^rd Infanterieregiment to urge the attack onward, was hit by a French shell and was evacuated. Breith, commander of the 5^th Panzerbrigade, was out of contact, so command devolved on von Boineburg-Lengsfeld, commander of the 4^th Schützenbrigade. At about 14.00, Hoepner passed on the order to stop the offensive, but did not halt the effort of the 3^rd Panzerdivision in the Ernage area and began to plan a new attack with the addition of 35^th Division and 20^th Division.

Having begun the day with too great a degree of optimism, the German command now swung to the other extreme. The 6^th Army refused the request of the XVI Corps (mot.) to renew the attack during the morning of the following day in favour of an set-piece attack by the whole army, which could not begin before 17 May. There were solid reasons for delay: the corps' artillery commander noted German difficulties in locating and neutralising French batteries, and added that as a result of the indifferent road network logistics units could not make good the German forces' heavy consumption of ammunition.

The war diary of the 4^th Panzerdivision makes clear the extent of the defeat. From 11.07, radio contact with the staff of the 5^th Panzerbrigade was lost. Breith was out of contact and reports from the front showed that the tanks were taking heavy losses and could not remain standing under fire. Thus, at 12.00 the division ordered the armour back to its start positions. At 13.00, the 4^th Schützenbrigade reported that the infantry was likewise pulling out. but von Boineburg-Lengsfeld ordered it forward again. It was at this point that Stever went forward, only to return, wounded in the face by a shell fragment, to his headquarters at 14.00. At 15.00, the 4^th Panzerdivision reported to the XVI Corps (mot.) that its Panzer brigade’s staff was stuck on the railway line. The 4^th Schützenbrigade also had suffered heavy losses and there was no prospect of success and it was doubtful that the troops could attack again on 16 May. At 15.40, Breith arrived at the divisional headquarters. He had spent three hours in a shell hole playing dead under heavy artillery fire. Stever was convinced a renewed attack on 16 May would not be possible. At 20.00, the XVI Corps (mot.) notified the 4^th Panzerdivision that the attack was to be renewed only on 17 May, but without the 4^th Panzerdivision. That afternoon, Hauptmann von Jungenfeld, one of the company commanders, sent a tank to try to rescue Breith, but the machine was hit four times and had to withdraw. Several companies were pinned down under fire.

Eventually, several German medium tanks crossed the anti-tank obstacle in front of a large factory which the German artillery had shelled, and under cover of the guns' fire the infantry started to advance. But French anti-tank guns engaged the tanks, which abandoned the infantry. Finally the infantry attempted to charge forward, moving into close contact with the French infantry, but they could advance no more than a short distance in the area of a railway, and as darkness fell the infantry retreated.

The situation of the 3^rd Panzerdivision was different. It had committed only a fraction of its tanks and one of its three infantry battalions had not yet been heavily engaged. During the afternoon, the 3^rd Panzerdivision was troubled by reports from the neighbouring 18^th Division of French armoured counterattacks toward the division’s right flank. At 13.00, 88-mm (3.465-in) guns and tanks of the 5^th Panzerregiment moved to the area of Perbais to ward off this threat. At 15.55 air reconnaissance reported French tanks and infantry on the railway line between Ernage and Chastre despite the fact that the French fighter had disrupted the sortie. At 16.48, the 3^rd Panzerbrigade reported effective French artillery fire. At 18.00, units of the 3^rd Schützenbrigade began to withdraw from Perbais. The 3^rd Panzerbrigade ordered tanks forward to stem the retreat, but at 18.20 the 3^rd Panzerbrigade reported breaking through the anti-tank obstacle to the north-west of Ernage under heavy fire and a French armoured counterattack from the west, and called for artillery support. At almost the same instant, the 18^th Division reported French armour attacking on both sides of Corbais. At 20.00, a captured French map arrived, and this revealed the French dispositions. The intelligence officer of the 3^rd Panzerdivision came to the conclusion that the situation was ripe for an attempt to break through, and travelled to corps headquarters to propose this. As noted above, however, the proposal contradicted orders from the 6^th Army and was dropped. Most of the tanks spent the day on standby around Orbais.

As the infantry of the 3^rd Panzerdivision began to withdraw from Perbais during the afternoon, spurred on by French artillery, there arrived reports of approaching French armour. But then the situation changed complexion. Two companies of the 3/3^rd Infanterieregiment moved with a company or so of tanks from Ernage to the west at about 18.00. Despite intense French resistance from Chastre, where German sources reported a few French tanks, the German infantry succeeded in reaching two hills to the west of Noirmont, the 3^rd Panzerdivision's original objective on 14 May, pulling forward with them elements of a battalion which had been holding the line. A French tank and infantry counterattack struck their open flank. The 6^th Panzerregiment sent forward reinforcements, these including one PzKpfw III medium tank and five PzKpfw I light tanks.

The Germans learned of the presence of French armour from Luftwaffe reconnaissance. Some 12 French tanks followed by Moroccan infantry attacked the Germans from the flank. The Germans claimed to have destroyed six tanks and dispersed the Moroccans. Following this, a machine gun company drove forward 1.25 miles (2 km) without loss, capturing much matériel but running out of ammunition. At that point, German accounts claim, French fire reopened on them and two French tanks appeared, destroying the PzKpfw III and three of the PzKpfw I machines. After this, a German battalion was halted in front of the French defence of the Cortil-Noirmont area. At 20.54, an order arrived from the XVI Corps (mot.) to stop the attack, followed by another from the brigade to withdraw behind the railway line.

Hoepner finally ordered the forward units of the 3^rd Panzerdivision to hold their positions. In the meantime, however, almost the whole of the 3^rd Infanterieregiment and its supporting tanks had pulled back. the 1/3^rd Infanterieregiment and 2/3^rd Infanterieregiment were exhausted and had not been resupplied for 36 hours. The opportunity to break through the French defences, if it ever really existed, was lost.

From the point of view of the Division Marocaine, the afternoon saw bitter fighting on the northern flank. Its weakest point was on the left at Ernage, where the 1/7ème Régiment d’Infanterie Marocaine had one of its companies encircled in the village. It had lost contact with the neighbouring 110ème Régiment d’Infanterie at 12.00 when German infantry crossed the railway line between Ernage and Perbais. At 12.30, the company effected a retreat to the headquarters of the 2/7ème Régiment d’Infanterie Marocaine, holding the stop line at Cortil-Noirmont. In Ernage, the last 12 men, all wounded and including their commanding officer, of the 7ème Régiment d’Infanterie Marocaine fought until 18.00, when they finally surrendered after they had exhausted all means of defence.

Mellier had originally intended to counterattack on his left with tanks of de La Font’s brigade and the 3/7ème Régiment d’Infanterie Marocaine. On learning that no tanks were available, Mellier had the 3/7ème Régiment d’Infanterie Marocaine reinforce the defence behind Ernage, although dive-bomber attacks slowed the battalion’s movement despite the intervention of one fighter, which shot down two dive-bombers. At about 14.00, the reserve re-established contact with a company of the 110ème Régiment d’Infanterie at Villeroux, but the situation remained critical and the headquarters of the 7ème Régiment d’Infanterie Marocaine and its supporting artillery battalion began to retreat toward St Gery. It was at this juncture that Mellier arrived on the stopline on his motorcycle. Under fire, he rallied the unit and, along with the divisional artillery, stopped the withdrawal. At 16.00, the remaining two companies of the 1/7ème Régiment d’Infanterie Marocaine fought their way back and extended the front toward Chastre, thereby stabilising the situation. The 3/7ème Régiment d’Infanterie Marocaine was ordered back to dig in at Les Communes, although German artillery fire, profiting from the spotting of an observation balloon, wounded the battalion commander. The 1/2ème Régiment d’Infanterie Marocaine to the right also suffered heavily, and there emerged signs of panic among the savaged unit. Mellier sent word that a counterattack would support them and that they were therefore to hold. At about 13.00, powerful German air attacks followed by renewed tank and infantry assaults struck the Moroccans, while the air attacks delayed the French counterattack. The two French companies on the railway line were overrun, but the Germans got no farther than the sunken road several hundred meters to the rear. The 5ème Compagnie at Cortil-Couvent noted heavy weapons abandoned by their crews. The 1ère Compagnie of the 1/2ème Régiment d’Infanterie Marocaine retreated that evening to the stopline, where the last available rifle ammunition was distributed.

Meanwhile, the counterattack which Mellier had ordered at 11.30 began, the 35^th Tank Battalion attacking with the 3/2ème Régiment d’Infanterie Marocaine. The attack was mounted from reserve positions some 5 miles (8 km) from its objective, the railway line from Ernage to Gembloux. This arrangement violated Aymes’s Operations Order No. 4 of 13 May demanding immediate counterattacks against Panzer incursions. The Moroccans' 9ème Compagnie was to attack on the left with one company of R35 tanks, and the 11ème Compagnie with another company of Renault tanks on the right, while the 10ème Compagnie and the battalion’s heavy weapons company were held in reserve. Each company received a section of machine-guns and one 25-mm anti-tank gun. A special detachment was to cover the open northern flank of the counterattack force.

The attackers assembled at 14.30 and reached the stopline at about 16.30. The long progress of this force forward from the rear made surprise impossible, as as soon as it reached the stopline the force was hit by massive bombing: the tank battalion’s chief-of-staff, claimed that 80 bombers were involved. One tank was overturned and the artillery support was disrupted, but the attack continued. The German air assaults separated the French tanks and infantry, something French doctrine forbade, and German combined-arms fire stopped the attack. The Moroccan infantry went to ground, there was little support from artillery and the French command tank had been knocked out in a French minefield. The tanks took the German anti-tank defences by surprise, but were unable to make progress. By 18.30, the attack was over.

So far, the 1ère Armée had held its own against all odds, but the rapid German penetration at Sedan to its south threatened its flank and rear, and the tanks of the 2ème Division Légère Mécanique, most of the reconnaissance battalions and even some of the infantry reserves were siphoned off to cover the deepening right flank. That morning Billotte warned the 1ère Armée to prepare to retreat if circumstances dictated. Pivoting on Wavre, at about 20.00 the 1ère Armée received the order to begin a phased withdrawal to the Franco/Belgian frontier. Meanwhile, the IV Corps d’Armée provided a defensive screen and fought off the German tanks.

At 14.00, the IV Corps d’Armée received erroneous reports that Perbais and Chastre had been lost and thus contact between the 7ème Régiment d’Infanterie Marocaine and the 110ème Régiment d’Infanterie was broken. While the battle thus approached its climax, the IV Corps d’Armée received the order at 15.00 to begin to retreat on its right. At the same time, the 3/7ème Régiment d’Infanterie Marocaine, in reserve, was engaged at Cortil-Noirmont while attempting to re-establish liaison with the 110ème Régiment d’Infanterie. At 16.00, a counterattack with 35^th Tank Battalion and the 3/2ème Régiment d’Infanterie Marocaine was launched. Although the infantry lost heavily and only a handful of tanks survived, Aymes was mistakenly informed that the main position of resistance had been re-established. At 18.00, new German attacks were reported against the 7ème Régiment d’Infanterie Marocaine, a few Panzers infiltrating as far as St Gery, where they were checked by elements of the divisional reconnaissance battalion.

At the same time, the regiments of the 15ème Division d’Infanterie Motorisée received orders for their retreat that evening, while at 18.30 they checked an armoured attack on Beuzet with artillery and anti-tank fire. At 20.00, the Division Marocaine issued orders for the withdrawal of the division, while the 7ème Régiment d’Infanterie Marocaine counterattacked a last German assault with success. German infantry before Gembloux began withdrawing. That night both sides pulled back, the Germans to escape the opponent to their front, the French to escape the opponent on their right rear, easing the disengagement of the Division Marocaine.

Along the front the German assault had been checked. At no time did the German thrust reach the French artillery positions, the backbone of the latter’s defence, which remained intact. Meanwhile, von Schwedler’s IV Corps had been prevented from crossing the Dyle river to the north. Of the crossings, only Limal remained in German hands by 00.00. The 19^th Infanterieregiment of the 7^th Division was also forced to abandon its position here at a time early on 16 May. The III Corps d’Armée had sometimes struggled to prevent a breakthrough, but succeeded despite serious German efforts. Major General H. C. Loyd’s British 2^nd Division delivered a counterattack that panicked the 31^st Division and a powerful British artillery bombardment allowed the 2ème Division Marocaine to disengage, which it did under cover of darkness and unhindered. The British contribution, though not part of the 'Battle of the Gembloux Gap', aided the French retreat.

The Allied success in the Gembloux gap was nullified by the German victory farther to the south, but von Reichenau’s failure to destroy or at least to defeat the Allied corps at Gembloux was crucial. While it is true that the Allied high command proved unable in the days following to utilise the corps to restore the Allied front, it took the Germans another two weeks of fighting to encircle and capture part of the 1ère Armée, allowing the rest and the bulk of the British Expeditionary Force to escape to Dunkirk.

During the 'Battle of the Gembloux Gap', the 3^rd Panzerdivision had suffered the loss of some 20 to 25% of its armoured fighting vehicles knocked out, and the 4^th Panzerdivision had suffered the loss of some 45 to 50% of its armoured fighting vehicles. the 12^th Infanterieregiment of the 4^th Panzerdivision had lost one-third of its officers, and the 1/12^th Infanterieregiment was left with just four officers and 31 men from a complement of 700. The 3^rd Infanterieregiment of the 3^rd Panzerdivision lost 15 officers and 184 other ranks. The overall losses for the 4^th Panzerdivision on 15 May were 105 men dead, 413 wounded and 29 missing. In the Division Marocaine, the 1/2ème Régiment d’Infanterie Marocaine ended the battle with 74 men out of its establishment of 700 men; the 1/7ème Régiment d’Infanterie Marocaine had only 80 men left, and the 2/7ème Régiment d’Infanterie Marocaine had just 150 men. In overall terms, the Division Marocaine lost about 2,000 men, or 27% of its strength, as casualties. The IV Corps d’Armée suffered a few hundred casualties, and the III Corps d’Armée rather more.