The Battle of Hannut

On 12 May 1940, Whit Sunday, a battle began on the flat farmland of the Hesbaye plain in central Belgium, between the small towns of Hannut and Tienen (Tirlemont in French), which the American historian Jeffrey Gunsburg called the “first great tank battle” of the Second World War. Facing each other were General René Prioux’s French Cavalry Corps, with two light mechanised divisions, and General Erich Hoepner’s German XVI Army Corps (motorised), with the 3rd and 4th Panzer Divisions. More than a thousand tanks fought on the two sides combined. That same day, a few dozen kilometres to the south, Belgian sappers were blowing the last bridges over the Meuse, and the first German units to have passed through the Ardennes were reaching the river near Dinant.

Some war chronologies record under 12 May that the Belgians blew up all the bridges over the Meuse to halt the German advance, and that the battle of Hannut began. The second statement is accurate. The first needs qualifying. The Meuse bridges were destroyed not on a single day but gradually, from 10 to 12 May, as the Germans approached, and not all of them by the Belgians: the three bridges in Dutch Maastricht, the most important on the route of the German 6th Army, were blown by the Dutch on the morning of 10 May. Most significant of all, moreover, was what could not be destroyed: two bridges over the Albert Canal at Veldwezelt and Vroenhoven, captured intact by German paratroopers, and the weir on the Meuse at Houx, across which infantry coming out of the Ardennes crossed during the night of 12–13 May.

The Meuse bridges

Belgium’s defence plan was based on rivers and canals. All the bridges over the Albert Canal and the Meuse had been mined long before the war, and the orders for their destruction lay waiting in sealed envelopes. When at dawn on 10 May the Wehrmacht crossed the borders of the Netherlands, Belgium and Luxembourg, the sappers carried out their task in most places. On the most important sector, however – the Maastricht “appendix”, where the German 6th Army was to cross the Meuse and the Albert Canal – things turned out differently. The Dutch blew all three bridges in Maastricht, despite attempts by disguised German saboteurs to seize them, and the German 4th Panzer Division had to wait for engineers, who built a pontoon bridge during the night of 10–11 May. Beyond the Meuse, on the Albert Canal, gliders carrying assault troops landed beside three bridges and on the roof of Fort Eben-Emael. The Belgians managed to blow the bridge at Kanne, but the bridges at Veldwezelt and Vroenhoven fell into German hands intact. Over them, and then over the pontoon bridge at Maastricht, the divisions of General Walter von Reichenau’s 6th Army poured in the following days.

It was these bridges that the Allies tried at all costs to destroy from the air. On 11 May they were attacked by Belgian Fairey Battle bombers, most of which were shot down. On the morning of 12 May five British Fairey Battles of No. 12 Squadron RAF, flown by volunteer crews, struck at the bridges at Veldwezelt and Vroenhoven. Only one aircraft returned from the attack. The Veldwezelt bridge was damaged but not destroyed. The pilot of the leading aircraft, Flying Officer Donald Garland, and his navigator, Sergeant Thomas Gray, were killed. Both were posthumously awarded the Victoria Cross, the first awarded to RAF airmen in this war. That same day the French air force lost several of the eighteen new Breguet 693 bombers it sent over the area. The attacks did not stop the German advance, and the Allied air forces suffered losses from which they were long unable to recover.

Further south, along the Meuse, the Belgians withdrew according to plan and destroyed the crossings behind them. The Belgian III Corps left the fortified position of Liège, where only the fort garrisons remained, and the bridges in the city and further downstream, at Huy and Namur, went up once the last units had crossed them. What happened on 12 May on the Namur–Givet sector, where the Meuse was to be defended by the French 9th Army, mattered most. In the afternoon of that day the advance guards of the German XV Corps, the 5th and 7th Panzer Divisions, reached the river. At Houx Belgian sappers blew the railway bridge at 2.45 p.m., less than two hours before the Germans arrived, and in Dinant the bridge opposite the collegiate church of Notre-Dame was destroyed shortly after four o’clock, ahead of the arrival of General Erwin Rommel’s 7th Panzer Division, which reached the river towards evening. The bridges were gone, but at Houx a weir with a lock island survived. During the night of 12–13 May German motorcyclists used it to cross to the left bank and seized the first bridgehead beyond the Meuse before the French infantry had time to settle into position on that sector. Blowing the bridges thus delayed the Germans by a dozen or so hours at most. Only a defence on the river itself could stop them, and on the sector of the 9th and 2nd Armies that defence was weak.

The Cavalry Corps moves forward

Under the Dyle Plan, put into effect from the morning of 10 May in its Breda variant, General Georges Blanchard’s French 1st Army was to occupy the so-called Gembloux Gap near Gembloux – an open plain between Wavre and Namur, without natural obstacles, along which for centuries armies marching from Germany on Paris had passed. Its infantry divisions needed several days to get there and dig in. That time was to be bought for them by General Prioux’s Cavalry Corps, pushed far forward to the east to meet the oncoming Germans. Its task was to fight a delaying action and keep the enemy away from the Gembloux area until dawn on 14 May.

The corps was the most modern large armoured formation in the French army. It consisted of General Gabriel Bougrain’s 2nd Light Mechanised Division (2e DLM) and General Jean-Léon-Albert Langlois’s 3rd Light Mechanised Division (3e DLM). The latter had been formed only on 1 February 1940 from reservists and was poorly trained, because the experienced 1e DLM had been sent in March to the 7th Army for the march towards the Netherlands. According to various tallies, the two divisions together had between about 415 and more than 500 tanks, plus several dozen Panhard armoured cars. The most valuable were 176 Somua S35 medium tanks, fast and well armoured, with a 47 mm gun that no German tank of 1940 could withstand. Most, however, were light Hotchkiss H35s and H39s, armed with a short 37 mm gun that was powerless against armour. The weak points of the French tanks were their one-man turrets, in which the commander had to load and fire the gun himself, and the lack of radios in most vehicles.

On the German side, Hoepner’s XVI Corps had General Horst Stumpff’s 3rd Panzer Division and General Johann Joachim Stever’s 4th Panzer Division, some 620 battle tanks in all. More than three-quarters of them, however, were light Panzer Is and IIs, armed with machine guns or a 20 mm cannon. The real strength lay in just over 80 Panzer IIIs and 50 Panzer IVs. The German advantage lay elsewhere: radios in the tanks, three-man turrets, more artillery and, above all, air power. Hoepner was supported by General Wolfram von Richthofen’s VIII Air Corps, with some three hundred Junkers Ju 87 dive-bombers.

Hoepner’s task was more important in the German plan than his opponents knew. He was to strike at Gembloux before the French could dig in there, but above all he was to convince the Allies that the main thrust was coming through central Belgium, as in 1914. The more of the best French troops he tied down in Belgium, the easier it would be for Army Group A to break through the Ardennes and the Meuse further south.

At the very outset Prioux made a mistake that weighed on the course of the fighting. Instead of concentrating his tanks and manoeuvring with them, he stretched both divisions along a front some 35–40 km long, from Tienen in the north through Hannut to Huy on the Meuse, in a chain of strongpoints in villages, with the tanks distributed among them in groups of a dozen or so. The French cavalry manual, co-written by General Langlois himself, warned that on open ground, in the face of superior armoured forces, a light mechanised division should not defend a sector wider than 10–15 km. The 3e DLM was given 17 km.

The first day: 12 May

On the morning of 12 May the spearheads of the 4th Panzer Division reached Hannut. General Stever, who did not yet have all his artillery and infantry and was short of fuel (he had asked for supplies by air), judged that he faced a single French battalion, and attacked. The French gave up Hannut itself without a fight, but in the surrounding villages – Crehen, Thisnes and Wansin – the dragoons’ strongpoints, supported by Hotchkiss tanks and artillery, put up a stubborn defence. At Crehen some fifty light German tanks tried to outflank the French position. The Hotchkiss crews of the 2nd Cuirassiers lost their commander but held on, and in the afternoon the encircled detachment was relieved by a counter-attack of Somua tanks from the 2e DLM, which broke through the German line at the cost of heavy losses.

In the evening the 3rd Panzer Division joined the fighting, and Reichenau ordered Hoepner to press on towards Gembloux. The German advance guard, a tank battalion and a rifle battalion, attacked Thisnes (PL). It was held up by French artillery fire, and when it finally reached the western edge of the village, the Somuas counter-attacked, hitting among others the regimental commander’s tank. The fighting went on until dusk, with the tanks of both sides blundering about in the darkness and running into one another. Wansin held out all night and was abandoned only towards morning. At eight in the evening Stever reported to Hoepner that he had two French mechanised divisions in front of him. They decided to attack together the following day, with the whole corps and full air support. The first day, as the German historian Karl-Heinz Frieser observes, was won by the French: Hoepner had not reached his objective, and the French line, apart from a single gap at the junction of the divisions, remained intact.

That same day, however, a matter more important than the fate of a few villages was decided. On the afternoon of 12 May General Alphonse Georges, commander of the north-eastern front, shifted the priority of French fighter aviation from the Belgian plain to the threatened sector on the Meuse near Sedan. Prioux’s cavalry was left almost without air cover. That morning, at a conference in a château near Casteau close to Mons, King Leopold III, the French Minister of National Defence Édouard Daladier, General Georges, General Gaston Billotte and Lord Gort’s chief of staff, General Henry Pownall, agreed that Billotte, commander of the 1st Army Group, would co-ordinate the operations of all the Allied armies in Belgium, the Belgian and British included. The Belgian army was to defend the sector from Antwerp to Leuven, extending the French and British line.

The second day: 13 May

On 13 May Hoepner concentrated both panzer divisions, some 560 serviceable tanks in all, together with the 18th Infantry Division from the neighbouring corps, on a sector less than 12 km wide, facing the 3e DLM. The French tanks, scattered along the whole front, could not respond in kind. From the morning Stukas circled over the French dragoons’ strongpoints, and after bombing and an artillery barrage, at around noon, the tanks of the 3rd Panzer Division attacked Orp and Marilles on the Petite Gette stream, while those of the 4th attacked Thisnes and Merdorp (PL).

After an hour and a half of fighting the German tanks managed to cross the stream. The French sector command ordered a withdrawal, and the Hotchkisses of the 1st Cuirassiers counter-attacked and threw the Germans back to the water, losing roughly as many vehicles as they destroyed. When Lieutenant Colonel de Vernejoul sent several dozen Somuas against the Germans advancing from Orp towards Jandrain, they ran into an equal number of German tanks waiting in concealment. In the open fields near Jandrain the fiercest clash of the battle was fought. The Somuas were resistant to German shells, and German tank crews recalled their hits bouncing off the French armour. The Germans, however, had numerical superiority, radio communications and the support of anti-tank guns and 88 mm anti-aircraft guns used against tanks. The French tanks fought in small groups, often without co-ordination. At Merdorp and Jandrenouille the Germans bypassed the French strongpoints, and the 2e DLM, preoccupied with the threat on its right flank on the Meuse near Huy, where German infantry was infiltrating, was unable to strike the exposed flank of the 4th Panzer Division.

In the afternoon the 3e DLM began to withdraw westwards, followed by the 2e DLM. In the evening the 3rd Panzer Brigade reported the destruction of 54 French tanks for “negligible” losses of its own. The Germans took several hundred prisoners. During the night and on the morning of 14 May the Cavalry Corps fell back behind the Belgian anti-tank obstacle on the Beauvechain–Perwez line, and on 14 May, in rearguard actions near Perwez, it handed over the defence to the divisions of the 1st Army, which had by then taken up position in the Gembloux Gap. This is why some historians date the battle to 12–13 May and others, counting the withdrawal fighting, to 12–14 May.

Losses and assessment

The balance of losses is disputed and depends on what is counted. According to Frieser, the Cavalry Corps lost about 105 tanks and the Germans about 160 tanks disabled, of which, however, only some 49 were total losses. The Germans recovered and repaired the rest, because the battlefield remained in their hands, whereas the French had to abandon every damaged vehicle. Other authors give higher French figures: the American historian Steven Zaloga puts the losses of the 3e DLM alone on 12–13 May at 105 tanks (68 Hotchkisses and 37 Somuas), and the German historian Roman Töppel estimates the total losses of the Cavalry Corps at some 200 vehicles, against 49 German. The dragoon regiments, broken up in the villages by aircraft and artillery, also suffered heavy losses.

Assessments of the battle were ambiguous from the start. The French could speak of success. The Cavalry Corps had accomplished its task: it had held the Germans for two days, and the 1st Army had time to take up position at Gembloux. The Somua proved a better tank than any German one. The Germans, for their part, showed that better tactics, communications and co-operation with the air force counted for more than the thickness of armour. The French tanks fought singly or in small groups, tied to strongpoints like infantry in the First World War. The German tanks, directed by radio, concentrated where they could be decisive. The French historian Robert Frank called Hannut a technical and tactical French victory but a strategic defeat: the best French armoured units allowed themselves to be tied down on the Belgian plain exactly where the German plan wanted them, and not where the fate of the campaign was being decided.

Place in the war

As the fighting at Hannut was coming to an end, on the afternoon of 13 May the Germans were forcing the Meuse at Sedan, and during the night of 12–13 May they had already crossed it at Houx. Both French light mechanised divisions, which might have been needed for a counter-attack in the Ardennes, were far to the north and weakened by their losses. On 14 and 15 May the French 1st Army repulsed the attack of Hoepner’s corps at Gembloux, but it was by then too late for this victory to matter: the breakthrough on the Meuse threatened its rear, and on the evening of 15 May it was ordered to withdraw. The Allies abandoned the Dyle Line, on 17 May the Germans entered Brussels, and on 20 May the panzer divisions advancing from Sedan reached the Channel, encircling the armies that had entered Belgium.

Hannut has gone down in history as the first battle in which two large armoured formations clashed in the open field, although individual tank engagements had already taken place in Spain and in Poland. Its lessons – the value of radio communications, concentration of force and co-operation between tanks and aircraft – were learnt by every army in the world in the years that followed. The French Cavalry Corps, diminished after Hannut and the fighting that followed, went on to cover the retreat of the northern armies into Flanders, and General Prioux himself, appointed commander of the 1st Army at the end of May, was taken prisoner together with its staff. Belgium, whose Meuse bridges went up between 10 and 12 May, remained under German occupation until September 1944.