The Battle of Hannut was a Second World War battle fought during the Battle of Belgium which took place between 12 and 14 May 1940 at Hannut in Belgium. It was the largest tank battle in the campaign. It was also the largest clash of tanks in armoured warfare history at the time.
The primary purpose of the Germans was to tie down the strongest elements of the French First Army and keep it away from the main German attack by Army Group A through the Ardennes, as laid down in the German operational plan Fall Gelb (Case Yellow), by General Erich von Manstein. The German breakout of the Ardennes was scheduled for 15 May, five days after the German attacks on the Netherlands and Belgium. The delay was to entice the Allies into believing the main thrust would, like the Schlieffen Plan in World War I, come through Belgium and then down into France. When the Allied armies advanced into Belgium according to the Dyle Plan, they would be tied down by German offensive operations in eastern Belgium at Hannut and Gembloux. With the flank of the First Army exposed, the Germans could thrust to the English Channel which would encircle and destroy the Allied forces. For the French, the plan in Belgium was to prepare for a prolonged defence at Gembloux, about west of Hannut. The French sent two armoured divisions forward, to conduct a delaying action against the German advance and give the rest of the First Army time to dig in at Gembloux.
The Germans reached the Hannut area just two days after the start of the invasion of Belgium but the French defeated several German attacks and fell back on Gembloux as planned. The Germans succeeded in tying down substantial Allied forces, which might have participated in the Battle of Sedan, the attack through the Ardennes. The Germans failed to neutralise the French First Army completely at Hannut, despite inflicting significant casualties. The French forces successfully delayed the German advance while allowing the First Army to situate itself at Gembloux, where, a couple of days later, the German advance lost over a third of its armor in combat.
The French once again scored tactical successes at the Battle of Gembloux from 14–15 May. In the aftermath of that battle, although seriously damaged, the First Army was able to retreat to Lille, where it delayed the Germans in the Siege of Lille and was instrumental in the re-embarkation of the British Expeditionary Force, French and Belgian troops at the Evacuation of Dunkirk.
Background
Allied intentions
The Allied supreme commander General Maurice Gamelin committed his First Army Group, under General Gaston Billotte, and its strongest Army, the French 1st Army under General Georges Blanchard with the fully mechanised Corps de Cavalerie (Cavalry Corps), commanded by General René Prioux, to advance into Belgium to support the large but more lightly equipped Belgian Army. Gamelin expected the German attack to break the Belgian defences at the Albert Canal line rapidly—the Belgians had in any case indicated they would after four days withdraw to the planned allied front in central Belgium, the "Dyle Line" between Antwerp and Namur—and sought to quickly establish an entrenched front line centred on Gembloux, just north of Namur, to check what Gamelin foresaw as the main enemy effort (Schwerpunkt) of the campaign: an attempt to break through the "Gembloux Gap" between the rivers Dyle and Meuse with a concentration of armoured forces. As Belgium, the Netherlands, and Luxembourg would remain neutral until the German invasion of those countries (Fall Gelb), it had proven impossible to adequately prepare positions for the French 1st Army. Therefore, the Cavalry Corps was given the mission to execute a delaying battle, somewhere between Gembloux and Maastricht (the likely crossing-point, where the Albert Canal connected to it, over the eastern bend of the Meuse), to prevent the enemy from reaching the Gembloux area until the eighth day of an invasion and to allow the 1st Army sufficient time to dig in.
The Cavalry Corps had been created on 26 December 1939, containing both then existing armoured divisions of the Cavalry, the 1re Division Légère Mécanique ("1st Mechanised Light Division") and the 2e DLM. On 26 March 1940 however, 1st DLM was given the mission, in case of an invasion, to establish a connection with the Dutch Army near Breda; this experienced active division was therefore removed from the Cavalry Corps. It was replaced by the 3e DLM, recently constituted on 1 February, manned with reservists and still insufficiently trained. Nevertheless, Prioux still considered his forces sufficient to either contest a river-crossing at Maastricht, or wage a manoeuvre battle or, as a third alternative, defend an improvised line. He was at liberty to choose any option, provided the enemy was kept from Gembloux long enough. He decided to keep all possibilities open and act as the situation would demand.
German intentions
The German plan for this sector called for an assault by airborne and shock troops to take Fort Eben-Emael and the Meuse and Albert Canal bridges, thus opening a way through the Dutch and Belgian defences for the 4. Panzerdivision (4th Panzer Division), and bring the Albert Canal defensive line to a premature collapse. Once this breach was made, General Erich Hoepner's XVI Army Corps, and Army Group B would assume control of the 4th Panzer Division, the 3rd Panzer Division and the 20th Infantry Division. Hoepner's mission was to quickly launch his Corps from the bridgehead, seize the area around Gembloux before the French infantry divisions could entrench themselves there, and by thus conforming to the worst fears of the French High Command draw all modern Allied forces and their reserves to the north, away from the main thrust through the Ardennes. This would enable the German Army to cut the French First Army, the BEF and the Belgians off by a swift advance to the English Channel leading to a giant encirclement. The action was basically a feint to tie down the Allies in the north so they could not interfere with the main thrust through the Ardennes.
Opposing forces
Allied forces The Battle of Hannut became the largest tank battle of the campaign. The French DLMs had two Brigades Légères Mécaniques each.
One of these, the "combat" brigade, contained two tank regiments, each regiment having 2 medium tank squadrons equipped with the SOMUA S35, and 2 light tank squadrons fielding the Hotchkiss H35. Each squadron's organic strength was 44 S35s and 43 H35s; also eight armoured command vehicles were present.
The other brigade contained a reconnaissance regiment, equipped with 44 Panhard 178 armoured cars organised in two squadrons, and a mechanised infantry regiment equipped with 126 Laffly S20TL 6-wheeled truck personnel carriers. Three organic AMR 35 (Automitrailleuse de Reconnaissance) squadrons of 22 tanks each were also included as were three armoured command vehicles. The 2e DLM used AMR 35 tanks for this rôle, but as the production of this light tank had been discontinued, 3e DLM employed H35s instead.
Each DLM thus had an organic strength of 260 tanks and 44 Panhards.
The entire Cavalry Corps (France) had a total of 520 tanks: 176 SOMUA S35s, 172 Hotchkiss H35s, 66 AMR 35s + 66 H35s and 88 P 178s, including the organic matériel reserve.
The 3e DLM used modifié 39 versions, a swifter, improved version of the H35s, that today is often referred to as the "H 39", but also had a single AMR squadron of 22 vehicles of the slower original batch of four hundred, that were exclusively present in 2e DLM. Most Hotchkiss tanks of both versions were fitted with the short, 37 mm 21 caliber SA 18 gun, which proved a poor antitank weapon. Some platoon and squadron commander's vehicles had been fitted with the more powerful 37 mm 35 caliber SA 38 gun, totalling about a fifth of the total number of Hotchkiss tanks.
The organisation of 2e DLM was: 3e BLM as a combat brigade, with 13e Dragons and 29e Dragons tank regiments; the second brigade was 4e BLM with 8e Cuirassiers reconnaissance regiment and 1er Dragons mechanised infantry regiment. The 3e DLM had 5e BLM with 1er Cuirassiers and 2e Cuirassiers tank regiments and 6e BLM with 12e Cuirassiers reconnaissance regiment and 11e Dragons mechanised infantry regiment.
German forces
Like their French counterparts the German armoured divisions each had an armoured brigade (Panzer-Brigade) with two tank regiments (Panzer-Regimenter). The latter were divided into two tank battalions (Panzer-Abteilungen); each tank battalion had, apart from a staff company, two light companies of nineteen battle tanks, in theory mainly equipped with the Panzerkampfwagen III, and a medium company of fifteen battle tanks using the Panzerkampfwagen IV. Due to a shortage of these types, the positions were actually in majority filled with the light Panzerkampfwagen II and even Panzerkampfwagen I.
The exact numbers of each type on 10 May available to the German armoured divisions are known: 3rd Pz. Div. had 314 battle tanks in its 3. Panzer-Brigade consisting of 5. and 6. Panzer-Regiment: 117 PzKpfw Is, 129 PzKpfw IIs, 42 PzKpfw IIIs and 26 PzKpfw IVs; 4th Pz. Div. had 304 battle tanks in its 5. Panzer-Brigade consisting of 35. and 36. Panzerregiment: 135 PzKpfw Is, 105 PzKpfw IIs, 40 PzKpfw IIIs and 24 PzKpfw IVs.
XVI. Armeekorps thus had a total of 618 tanks: 252 PzKpfw Is, 234 PzKpfw IIs, 82 PzKpfw IIIs and 50 PzKpfw IVs. Besides these battle tanks, 3rd Pz. Div. had 27 Befehlspanzer tracked command vehicles with only machine-gun armament and 4th Pz. Div. ten. Each division also had about 56 armoured cars. Most PzKpfw IIs of XVI Armeekorps had not yet been uparmoured to the new 30 mm standard and were thus vulnerable to even the French 37 mm L/21 gun.
As the French mechanised infantry regiments had three mechanised infantry battalions, total infantry strength of the Corps de Cavalerie (CC) was six battalions. XVI. Armeekorps had seven motorised infantry battalions. The French units were only lightly equipped with antitank-guns: twelve 25 mm and eight 47 mm SA 37 guns per division; and anti-aircraft guns: six 25 mm guns per division. Also, there was an imbalance in artillery: the French Mechanised Light Divisions each had 36 pieces against 68 (including 24 7.5 cm leichtes Infanteriegeschütz 18) per Panzerdivision. This was not set off by Corps artillery; the Germans had four attached artillery regiments and a heavy battery; the French CC only two 75 mm field gun regiments (and a group of twelve 25 mm antitank-guns) as corps troops.
The specialized VIII. Fliegerkorps of the Luftwaffe, with some 300 Junkers Ju 87 dive bombers and 42 Henschel Hs 123 biplanes, plus some 130 Messerschmitt Bf 109 fighter aircraft, stood ready to support the Panzers. The IV. Fliegerkorps and IX. Fliegerkorps added some 280 medium bombers and over 500 Messerschmitt Bf 109 and Messerschmitt Bf 110 heavy fighters, some of which would also be at Hoepner's disposal.
Prelude to engagement
Prioux's mistake Billotte suggested to Prioux that he might move his armour further east to support the Belgian Army. But Prioux, unimpressed by the Belgian defence and fearing to concentrate his force in the open beneath a dominant Luftwaffe, preferred to deploy his dragoons and supporting arms further back in a line of strong points, with his tanks behind them to counterattack enemy penetrations. Billotte accepted his decision and, impressed by the need for haste, added that the First Army Group would advance by day as well as by night, despite the threat of the Luftwaffe, in order to reach Gembloux. Thus Prioux need stall the Panzers only until the dawn of 14 May.