Belgian Campaign

The Belgian campaign was the second German attack on Belgium within a quarter of a century and, as in 1914, it began with the violation of Belgian neutrality. At dawn on 10 May 1940 the Wehrmacht, without a declaration of war, struck at the Netherlands, Belgium and Luxembourg. The Belgian army, mobilised since the autumn of 1939 and several times larger than in 1914, was to hold the frontier on the Albert Canal and the Meuse until French and British troops arrived. On the very first day German glider-borne paratroops seized Fort Eben-Emael and the bridges over the canal, and after two days the Belgians had to fall back to the Dyle Line. There, together with their allies, they repulsed the first attacks, and at Hannut and Gembloux the French fought the first great tank battle of the war. Belgium’s fate, however, was decided elsewhere: the main German blow came through the Ardennes and fell on the French on the Meuse at Sedan, and the panzer divisions, driving towards the English Channel, cut off all the Allied forces fighting in Belgium from France. Retreating from line to line, the Belgians lost Brussels, Antwerp and Ghent, and in the last week of May they fought the bloodiest battle of the campaign on the Lys. On 28 May 1940 King Leopold III, the army’s commander-in-chief, surrendered unconditionally, against the position of his own government.

Name and dates

In Poland it is called the Belgian campaign; in Belgium it is the “Eighteen Days’ Campaign” (French campagne des 18 jours, Dutch achttiendaagse veldtocht), and in Britain it is usually called the Battle of Belgium. For the Germans it was part of the Western Campaign conducted under Case Yellow (Fall Gelb), and in Belgium itself the task of Army Group B. The campaign began on 10 May 1940 when, at about 4.30 a.m. Belgian time (5.30 a.m. German time), the Luftwaffe attacked Belgian airfields and gliders landed on Fort Eben-Emael and beside the bridges over the Albert Canal. The German ambassador in Brussels handed the Belgian government a note justifying the “protection of Belgian neutrality” only several hours after the offensive had begun.

The campaign is taken to have ended on 28 May 1940, when at 4 a.m. a ceasefire came into force following the unconditional surrender of the Belgian army. On a few isolated sectors the fighting went on a little longer. Fort Tancrémont near Liège, whose garrison did not know of the capitulation, surrendered only on 29 May. The Belgian campaign was part of the wider Battle of France, which lasted until 25 June. It comprised the fighting on Belgian soil involving the Belgian army and the Allied forces that came to its aid. The breakthrough on the Meuse at Sedan, fought on French territory, and the defence of Dunkirk are separate battles.

Background

Belgium, invaded by Germany in 1914, bound itself to France after the First World War by a secret military agreement of 1920. After the remilitarisation of the Rhineland in March 1936, to which Paris made no response, King Leopold III concluded that an alliance with a passive neighbour endangered Belgium more than it protected it. In October 1936 he proclaimed a “policy of independence”; in 1937 Britain and France released Belgium from its obligations under Locarno, and Germany gave assurances that it would respect Belgian territory. In September 1939 the government of Hubert Pierlot declared neutrality, and the King took personal command of the army. On 27 October, in a broadcast to the Americans, he announced that Belgium would fight if attacked.

Neutrality meant that the Belgians refused open staff talks with the French and British and would not let their troops onto Belgian territory. Meanwhile, on 9 October 1939, Adolf Hitler issued a directive to prepare an offensive through the Netherlands, Belgium and Luxembourg. The Allies responded with the Dyle Plan: at the signal of a German invasion the French armies of the 1st Army Group and Lord Gort’s British Expeditionary Force were to advance deep into Belgium, to the line Antwerp–Leuven–Wavre–Namur, and there, together with the Belgians, stop the Germans. On 10 January 1940, in the Mechelen incident, half-burnt German orders fell into Belgian hands, confirming that the main blow was to come through central Belgium. The alarm they caused, however, did not persuade Brussels to call in its allies.

After this episode the German plan changed fundamentally. Since the autumn Erich von Manstein had been urging that the main thrust be shifted to the Ardennes, and in February 1940 he won Hitler over. In the new version of Case Yellow the leading role fell to Colonel General Gerd von Rundstedt’s Army Group A, which with seven panzer divisions was to pass through the Belgian and Luxembourg Ardennes and force the Meuse between Dinant and Sedan. Colonel General Fedor von Bock’s Army Group B, striking at the Netherlands and central Belgium, was given a less spectacular but no less important task: it was to attack so violently that the Allies would believe the war was being decided here and commit their best armies to Belgium. From the Belgian point of view, then, the campaign was a trap from the outset. The better the Dyle Plan was carried out, the deeper the Allies went into a sack which the Germans intended to tie shut from the south.

Forces and plans

With an effort commensurate with a country of eight million, Belgium fielded some 600,000–650,000 soldiers in 22 divisions: 18 infantry divisions, two divisions of Ardennes Chasseurs (Chasseurs Ardennais) and two cavalry divisions, grouped in seven corps and a cavalry corps. The army had plenty of artillery and good 47 mm anti-tank guns but almost no tanks, and on 10 May the air force had some 180 aircraft, most of them obsolete. The King was in command, advised by General Raoul Van Overstraeten, and from February 1940 the chief of staff was Lieutenant General Oscar Michiels.

The Belgian plan provided for a delaying defence on the frontier and the main resistance on the line of the Albert Canal and the Meuse, covered by the forts of the Liège and Namur fortresses and by the modern Eben-Emael fortified group where the canal meets the Meuse, south of Dutch Maastricht. This line had to be held for a few days, until the Allies occupied the Dyle Line. The Belgian army was then to withdraw to the fortified KW Line between Antwerp and Leuven and defend its sector. The Ardennes Chasseurs in the south were merely to demolish roads and bridges in the Ardennes and then fall back behind the Meuse.

On the Allied side, three French armies and the BEF, several dozen divisions in all, under General Gaston Billotte’s 1st Army Group, were to enter Belgium. In the north General Henri Giraud’s Seventh Army was to hurry through Flanders as far as Breda in the Netherlands. The BEF, which in May had ten divisions deployed at the front, was to take the Dyle sector from Leuven to Wavre. The strongest force, General Georges Blanchard’s French First Army, was to occupy the Gembloux gap between Wavre and Namur, an open plain without natural obstacles. It was screened by General René Prioux’s Cavalry Corps with two light mechanised divisions and some four hundred modern SOMUA S35 and Hotchkiss H35 tanks. Further south the Ninth Army was to take up position on the Meuse from Namur to the French border.

Belgium was attacked by Colonel General Walter von Reichenau’s Sixth Army, which was to pass through the narrow Maastricht “appendix” and across the Albert Canal, and, after the Dutch capitulation, also by General Georg von Küchler’s Eighteenth Army. Reichenau’s fist was General Erich Hoepner’s XVI Corps with the 3rd and 4th Panzer Divisions, more than six hundred tanks in all, most of them light. At the same time forces of Army Group A, including the panzer divisions of General Heinz Guderian and Generalmajor Erwin Rommel, advanced through southern Belgium across the Ardennes towards the Meuse. From the first day the Luftwaffe had clear superiority over Belgium.

10–11 May: Eben-Emael and the Albert Canal

The attack on Eben-Emael and three bridges over the Albert Canal was the first operation in history in which the decisive task was entrusted to glider-borne troops. It was prepared by Hauptmann Walter Koch’s assault detachment, formed in the autumn of 1939 from soldiers of Generalleutnant Kurt Student’s 7th Air Division (PL). At dawn on 10 May several dozen DFS 230 gliders landed beside the bridges at Veldwezelt (PL), Vroenhoven (PL) and Kanne and on the flat roof of the fort. The Germans captured the bridges at Veldwezelt and Vroenhoven intact before the Belgians could blow them. At Kanne the defenders managed to destroy the bridge. Only a few dozen men of the Granit group landed on the fort, because two gliders, including the one carrying the commander, Oberleutnant Rudolf Witzig, had to land short. The sappers, led until Witzig’s arrival by Oberfeldwebel Helmut Wenzel, used shaped charges to destroy the cupolas and the gun casemates that could fire on the bridges. The garrison, some 750 men that day out of an establishment of more than a thousand, held out in the underground galleries, but around noon on 11 May, when German infantry fought its way through to the fort, it capitulated. According to the most commonly cited figures 23 Belgians were killed and 59 wounded. The Granit group lost 6 killed and some 20 wounded on the fort. The groups attacking the bridges suffered heavier losses, the heaviest at Kanne, where more than twenty of them were killed.

The Dutch, meanwhile, had blown the bridges over the Meuse at Maastricht, but German engineers quickly built crossings, and Stukas supported the paratroops in the bridgeheads. The Belgian 7th Infantry Division, defending the canal, tried to retake the bridges and suffered heavy losses. On 11 May Belgian aircraft, and then British and French ones, bombed the crossings without success, losing many machines. On the first day the Luftwaffe had also destroyed a large part of the Belgian air force on the ground. With the bridges lost and the Liège fortress in danger of being outflanked from the north, the Belgian command ordered a withdrawal from the Albert Canal to the KW Line on the evening of 11 May. The forts around Liège and Namur were left behind and held out for many more days, tying down German infantry.

In southern Belgium the Ardennes Chasseurs, as ordered, demolished roads and fell back behind the Meuse. Where, owing to broken communications, the order did not reach them, they resisted: at Bodange a single company held up the 1st Panzer Division for several hours. The French cavalry of the Ninth and Second Armies, sent into the Ardennes, withdrew to the Meuse after brief clashes. Belgian and French roadblocks delayed Guderian’s march only slightly. By the evening of 12 May the Germans were on the Meuse from Dinant to Sedan.

On the morning of 10 May the Belgian government appealed to France and Britain for help. General Maurice Gamelin ordered the Dyle Plan to be carried out in its Breda variant, and the Allied columns, greeted with flowers, crossed the Belgian frontier. The Luftwaffe scarcely interfered with them, which was later seen as a telling sign: the Germans wanted the Allies to enter Belgium.

12–16 May: Hannut, Gembloux and the Dyle Line

On 12 May King Leopold III, Van Overstraeten, the French Minister of Defence Édouard Daladier, the commander of the North-Eastern Front General Alphonse Georges, General Billotte and Gort’s chief of staff General Henry Pownall met at the Château de Casteau near Mons. They agreed that Billotte would coordinate the operations of all the armies in Belgium, the Belgian army included, and that the Belgians would hold the sector from Antwerp to Leuven.

That same day, at Hannut on the Hesbaye plain, Hoepner’s tanks clashed with Prioux’s Cavalry Corps, whose task was to delay the Germans for several days in front of the First Army’s line. The Battle of Hannut, which lasted from 12 to 13 May, or according to some authors until 14 May, was the first great tank battle of the war and the largest seen up to that time. According to the most commonly cited figures, some 620 German tanks fought some 410 French ones. The heavy SOMUA tanks were better armoured and armed than most German vehicles, predominantly light Panzer Is and IIs, but the Germans had radios, cooperation with the air force and the skill to concentrate their forces. On the first day the French held; on 13 May Hoepner concentrated his attack against the 3rd Light Mechanised Division, stretched out in a thin line, and broke through its defences. Prioux had nevertheless done his job: as planned, he withdrew behind the line of the First Army, which had had time to dig in. According to some historians the French lost about a hundred tanks and the Germans about 160 disabled, most of which they were able to repair, since the battlefield remained in their hands.

On 14 and 15 May Hoepner, without waiting for the infantry, attacked the First Army’s positions in the Gembloux gap. In the Battle of Gembloux the French infantry, including the 1st Moroccan Infantry Division and North African divisions, supported by powerful artillery, repulsed the attack of both panzer divisions, which suffered heavy losses. It was one of the few clear Allied defensive victories of May 1940. North of Gembloux the BEF repulsed attacks on 14 and 15 May on Leuven, held by General Bernard Montgomery’s British 3rd Division, and the Belgian army held its sector of the KW Line.

On the northern flank the Breda plan failed. Giraud’s Seventh Army reached the area of Breda on 11 May, but German paratroops already held the bridges at Moerdijk, and the 9th Panzer Division and the Luftwaffe drove the French back towards Antwerp. On 15 May the Netherlands capitulated. In the meantime, on 13 May, the Germans had forced the Meuse at Sedan and Dinant, and on 15 May they broke through the front of the French Ninth Army south of Namur. The Allied forces on the Dyle Line, though not themselves defeated, were now in danger of being outflanked from the south. On the evening of 16 May Billotte ordered a withdrawal behind the Scheldt in three night stages: to the Senne, to the Dender and to the Scheldt. The Belgians received the order with bitterness, for their position was holding firm and the retreat meant giving up Brussels and most of the country without a fight.

16–23 May: the retreat to the Scheldt

On 16 May the Pierlot government left Brussels and soon reached France. The King remained with the army. On 17 May the Germans entered Brussels, which had been declared an open city, and on 18 May they took Antwerp, whose fortress the Belgians had abandoned in the course of the retreat. On the same day, 18 May, Hitler signed a decree annexing to the Reich the districts of Eupen, Malmedy and Moresnet, which had been given to Belgium after the First World War. On 18 May Hoepner was ordered to hand over both his panzer divisions to Army Group A, which was racing towards the sea. Of the armoured forces, only the 9th Panzer Division remained on the Belgian front. Bock’s armies pressed on after the retreating Allies mainly with infantry.

On 19 May the Allies stood on the Scheldt. The Belgians held its lower course and a bridgehead around Ghent as far as the Terneuzen canal, the BEF the central sector, and the French First Army the southern wing. But on the evening of 20 May Guderian’s tanks reached the sea at Abbeville. The northern armies – the Belgians, the BEF, the First Army and the remnants of the Seventh and Ninth Armies, some one million men – were cut off from the main French forces. The new Commander-in-Chief, General Maxime Weygand, wanted to sever the German corridor with attacks from the north and the south. On 21 May he flew into the cut-off area and met Leopold III and Billotte at the town hall in Ypres. He demanded that the Belgians take over part of the front from the British and, if necessary, fall back to the Yser, freeing divisions for the attack. Gort arrived only after Weygand had flown out. That same evening Billotte was injured in a car accident; he died on 23 May. Blanchard took over the 1st Army Group, and Prioux the First Army. The British counter-attack at Arras on 21 May and uncoordinated French attempts failed to cut the German corridor.

The Belgians rejected a withdrawal to the Yser, which would have meant abandoning their supplies and almost the whole country and, as Van Overstraeten warned, the disintegration of an exhausted army. They did, however, agree to extend their front. On the night of 22/23 May the Allies left the Scheldt; the Belgians took up position on the Lys from Menen through Kortrijk to Ghent and then along the canals to the sea, and the BEF fell back to fortified positions on the French border. On this narrow strip of the country, with supply bases squeezed around Ostend and Nieuwpoort and roads choked with hundreds of thousands of refugees, the Belgian army fought its last battle. Around 23–24 May the Germans took Ghent.

24–28 May: the Battle of the Lys and the capitulation

On 24 May Bock threw four divisions of the Sixth Army against the Belgian sector at Kortrijk, at the junction with the British. After a heavy artillery preparation and air attacks the German infantry crossed the Lys and by evening had won a bridgehead some fifteen kilometres wide. Belgian counter-attacks on 24 and 25 May recovered some ground and took several hundred prisoners, but with the Luftwaffe in command of the air they could not throw the Germans back across the river. The Belgian command repeatedly asked the British for a counter-attack against the left flank of the attackers, passing on its requests through Admiral Roger Keyes, Churchill’s liaison officer with the King. The BEF, itself under threat and already preparing to withdraw towards the sea, did not do so. Instead, on 25 May Gort abandoned the southward attack envisaged in the Weygand plan and sent the 5th and 50th Divisions to the Comines–Ypres canal to close the widening gap between the British and Belgian armies.

On the morning of 25 May, at Wijnendale Castle near Torhout, the King met for the last time Prime Minister Pierlot, Foreign Minister Paul-Henri Spaak and two other ministers. They urged him to leave with them and, as head of state, to carry on the war alongside the Allies. Leopold III refused: he judged that the Allied cause in Belgium was lost and that his place was with the army. The meeting ended in a break between the King and the government. That day the King announced in an order to his troops that, whatever happened, he would share their fate.

On 26 and 27 May the front on the Lys began to give way. The Germans crossed the canal at several points and took Nevele, Tielt and Izegem, while near Deinze the Ardennes Chasseurs held out at Vinkt against the 56th and 225th Infantry Divisions. At Vinkt and neighbouring Meigem German soldiers, who had suffered heavy losses there, murdered several dozen civilians – 86 according to the most commonly cited figure. On 26 May the British began the evacuation from Dunkirk. The Belgian army, without reserves and running out of ammunition and food, had nowhere left to retreat. The scrap of the country that remained to it, less than 2,000 km² in area, was crowded with some three million people, including hundreds of thousands of refugees. At noon on 26 May the Belgian command informed the French military mission that the army had reached the limits of its endurance, and before noon on 27 May the front was broken in several places.

At 5 p.m. on 27 May Leopold III, on the advice of his chief of staff, Lieutenant General Michiels, sent the deputy chief of staff, General Olivier Derousseaux, to the German command to ask for the terms of a ceasefire. The Belgian command informed the Allied military missions at its headquarters, but the news reached Gort only late in the evening, and the Allies later claimed to have been taken by surprise. At 10 p.m. Derousseaux returned with Hitler’s answer, which demanded unconditional surrender. The King accepted it and proposed that firing should cease at 4 a.m. At that hour on 28 May the Belgian army stopped fighting. General Derousseaux signed the instrument of capitulation on behalf of the army. Leopold III accepted an unconditional military surrender as commander-in-chief, but concluded no political agreement with Hitler. He refused to leave the country and, as a prisoner, was soon confined in his palace at Laeken near Brussels.

The capitulation opened a gap some 30 km wide on the eastern side of the ring around Dunkirk, between Ypres and the sea, which the British hurriedly closed at Nieuwpoort. On 28 May the French Prime Minister Paul Reynaud sharply condemned the King in a radio broadcast, and Prime Minister Pierlot declared from Paris that Leopold III had acted against the unanimous advice of the government and, as a prisoner, could not exercise authority. The Belgian government in exile resolved to continue the war.

Losses

The exact losses of the Belgian campaign cannot be established, especially for the German, French and British forces, whose losses in Belgium were counted together with the rest of the campaign in the west. According to Belgian figures, the Belgian army lost some 6,100 killed, more than 15,000 wounded and some 500 missing in the eighteen days. The bloodiest engagement was the Battle of the Lys, in which, according to Belgian estimates, 2,500–3,000 soldiers were killed. Some 200,000 Belgian soldiers were taken prisoner, and according to some calculations, counting those detained after the capitulation, many more. In the following months the Germans released most of the Flemish prisoners, but held most of the Walloons and regular soldiers until 1945. Some 2,000 of them died in captivity. The Belgian air force lost more than a hundred aircraft.

German losses in Belgium are not known separately. According to the OKW’s returns, the Wehrmacht’s total losses in the whole campaign in the west from 10 May to 4 June amounted to more than 10,000 killed, some 8,500 missing and more than 42,000 wounded. A large share of them was incurred fighting the Belgian army and the French First Army: at Hannut and Gembloux Hoepner’s panzer divisions temporarily lost as many as half their tanks, and on the Lys the German infantry suffered some of the heaviest losses of the entire campaign.

Significance

For the Germans the Belgian campaign was a carefully prepared diversionary manoeuvre, and it fulfilled its purpose. The Wehrmacht drew the Allies’ best armies into central Belgium and held them there long enough for the panzer divisions of Army Group A to pass through the Ardennes and encircle them. Fort Eben-Emael, taken within hours by a few dozen paratroops, became a symbol of a new kind of warfare, although its fall was above all the result of surprise and of the lack of infantry cover on the fort’s roof. The battles of Hannut and Gembloux, for their part, showed that French troops could fight German panzer divisions effectively when they had a prepared position, but none of these tactical victories could change anything once the front had broken on the Meuse.

The Belgian army, often reproached by the Allies after the war for collapsing too quickly, held out longer than the Dutch army and, despite lacking tanks and aircraft, covered the eastern flank of the encircled Allied forces during the last week. The German official history spoke of the “extraordinary courage” of the Belgian soldiers. The Battle of the Lys gave the BEF time to withdraw towards Dunkirk. The capitulation of 28 May, however, laid bare the flank of the British and French and at once gave rise to mutual recriminations. In France there was talk of the King’s treachery, and Winston Churchill, who on 28 May had spoken with restraint in the House of Commons, on 4 June sharply reproached Leopold III for surrendering his army without warning his allies and exposing their flank. Most historians regard these charges as unjust: the Allies had known for several days that the Belgians were at the end of their strength, and the British had themselves been preparing a withdrawal to the sea without informing the Belgians.

In a wider perspective the Belgian campaign was one of the links in the chain of France’s defeat in May and June 1940. Its end marked the beginning of four years of German occupation of Belgium under the military administration of General Alexander von Falkenhausen. The Pierlot government, after the fall of France, moved to London in October 1940 and carried on the war alongside Britain, with the Belgian merchant fleet, the gold reserves and the resources of the Belgian Congo at its disposal. Belgian soldiers and airmen fought in the Allied ranks until the country’s liberation in September 1944. Leopold III’s conduct in May 1940 and during the occupation divided Belgians over the so-called Royal Question. Although a majority voted for his return in a referendum in 1950, protests and strikes, chiefly in Wallonia, forced him to abdicate in 1951 in favour of his son Baudouin.