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Dutch Air Forces

Training and readiness

Not only was the Dutch Army poorly equipped; it was also poorly trained. There had especially been little experience gained in the handling of larger units above the battalion level. From 1932 until 1936, the Dutch Army did not hold summer field manoeuvres in order to conserve military funding. Also, the individual soldier lacked many necessary skills. Before the war only a minority of young men eligible to serve in the military had actually been conscripted. Until 1938, those who were enlisted only served for 24 weeks, just enough to receive basic infantry training. That same year, service time was increased to eleven months. The low quality of conscripts was not compensated by a large body of professional military personnel. In 1940 there were only 1206 professional officers present; It had been hoped that when war threatened, these deficiencies could be quickly remedied but following the mobilisation of all Dutch forces on 28 August 1939 (bringing Army strength to about 280,000 men) readiness only slowly improved: most available time was spent constructing defences. During this period, munition shortages limited live fire training, while unit cohesion remained low. By its own standards the Dutch Army in May 1940 was unfit for battle. It simply could not stage a major offensive, let alone execute manoeuvre warfare.

German generals and tacticians (along with Hitler himself) had an equally low opinion of the Dutch military and expected that the core region of Holland proper could be conquered in about three to five days.

Dutch defensive strategy

Structural elements

The Grebbe line, a forward defense line of the Dutch Water Line, is shown in dark blue

In the seventeenth century, the Dutch Republic had devised an effective defensive system called The Dutch Water Line, which could protect all major cities in the west by flooding part of the countryside. In the early 19th century this line was shifted somewhat to the east, beyond Utrecht, and later modernised with fortresses. This new position was called the New Holland Water Line. The line was reinforced with new pillboxes in 1940 as the fortifications were outdated. The line was located at the extreme eastern edge of the area lying below sea level. This allowed the ground before the fortifications to be easily inundated with a few feet of water, too shallow for boats, but deep enough to turn the soil into an impassable quagmire. The area west of the New Holland Water Line was called Fortress Holland (Dutch: Vesting Holland; German: Festung Holland), the eastern flank of which was also covered by Lake IJssel and the southern flank protected by the lower course of three broad parallel rivers: two effluents of the Rhine, and the Meuse (or Maas). It functioned as a National Redoubt, which was expected to hold out a prolonged period of time, in the most optimistic predictions as much as three months without any allied assistance, even though the size of the attacking German force was strongly overestimated. Before the war the intention was to fall back to this position almost immediately, after a concentration phase (the so-called Case Blue) in the Gelderse Vallei, inspired by the hope that Germany would only travel through the southern provinces on its way to Belgium and leave Holland proper untouched. In 1939 it was understood such an attitude posed an invitation to invasion and made it impossible to negotiate with the Entente about a common defence. Proposals by German diplomats that the Dutch government would secretly assent to an advance into the country were rejected.

From September 1939 a more easterly Main Defence Line (MDL) was constructed. This second main defensive position had a northern part formed by the Grebbelinie (Grebbe line), located at the foothills of the Utrecht Hill Ridge, an Ice Age moraine between Lake IJssel and the Lower Rhine. It was dug on instigation of the commander of the Field Army Lieutenant-General Jan Joseph Godfried baron van Voorst tot Voorst. This line was extended by a southern part: the Peel-Raamstelling (Peel-Raam Position), located between the river Maas and the Belgian border along the Peel Marshes and the Raam rivulet, as ordered by the Dutch Commander in Chief, General Izaak H. Reijnders. In the south the intention was to delay the Germans as much as possible to cover a French advance. Fourth and Second Army Corps were positioned at the Grebbe Line; Third Army Corps were stationed at the Peel-Raam Position with the Light Division behind it to cover its southern flank. Brigade A and B were positioned between the Lower Rhine and the Maas. First Army Corps was a strategic reserve in the Fortress Holland, the southern perimeter of which was manned by another ten battalions and the eastern by six battalions. All these lines were reinforced by pillboxes.

Positioning of troops

The Peel-Raam Position

In front of this Main Defence Line was the IJssel-Maaslinie, a covering line along the rivers IJssel and Maas, connected by positions in the Betuwe, again with pillboxes and lightly occupied by a screen of fourteen "border battalions". Late in 1939 General Van Voorst tot Voorst, reviving plans he had already worked out in 1937, proposed to make use of the excellent defensive opportunities these rivers offered. He proposed a shift to a more mobile strategy by fighting a delaying battle at the plausible crossing sites near Arnhem and Gennep to force the German divisions to spend much of their offensive power before they had reached the MDL, and ideally even defeat them. This was deemed too risky by the Dutch government and General Reijnders. The latter wanted the army to first offer heavy resistance at the Grebbe Line and Peel Raam Position, and then fall back to the Fortress Holland. This also was considered too dangerous by the government, especially in light of German air supremacy, and had the disadvantage of having to fully prepare two lines. Reijnders had already been denied full military authority in the defence zones; the conflict about strategy further undermined his political position. On 5 February 1940 he was forced to offer his resignation because of these disagreements with his superiors. He was replaced by General Henry G. Winkelman who decided that in the north the Grebbe Line would be the main defence line where the decisive battle was to be waged, partly because it would there be easier to break out with a counteroffensive if the conditions were favourable. However, he took no comparable decision regarding the Peel-Raam Position.

During the Phoney War the Netherlands officially adhered to a policy of strict neutrality. In secret, the Dutch military command, partly acting on its own accord, negotiated with both Belgium and France via the Dutch military attaché in Paris, Lieutenant-Colonel David van Voorst Evekink to coordinate a common defence to a German invasion. This failed because of insurmountable differences of opinion about the question of which strategy to follow.

Coordinating with Belgium

Given its obvious strategic importance, Belgium, though in principle neutral, had already made quite detailed arrangements for coordination with Entente troops. This made it more difficult for the Dutch to coordinate with the Belgians. Reijnders refused to abandon without a fight his plan for the Belgians to connect their defences to the Peel-Raam Position. He did not approve of a plan by Van Voorst tot Voorst to occupy a so-called "Orange Position" on the much shorter line 's-Hertogenbosch – Tilburg, to form a continuous front with the Belgian lines near Turnhout as proposed by Belgian General Raoul van Overstraeten.

When Winkelman took over command, he intensified the negotiations, proposing on 21 February that Belgium would man a connecting line with the Peel Raam Position along the Belgian part of the Zuid-Willemsvaart. The Belgians refused to do this unless the Dutch reinforced their presence in Limburg; the Dutch had no forces available with which to fulfill this request. Repeated Belgian requests to reconsider the Orange Position were refused by Winkelman. Therefore the Belgians decided to withdraw, in the event of an invasion, all their troops to their main defence line, the Albert Canal. This created a dangerous gap forty kilometres wide. The French were invited to fill it. Now the French Commander in Chief General Maurice Gamelin was more than interested in including the Dutch in his continuous front as, like Major-General Bernard Montgomery four years later, he hoped to circle around the Westwall when the Entente launched its 1941 offensive. But he did not dare to stretch his supply lines that far unless the Belgians and Dutch would take the allied side before the German attack. When both nations refused, Gamelin made it clear that he would occupy a connecting position near Breda. The Dutch did not fortify this area. In secret, Winkelman decided on 30 March to abandon the Peel-Raam Position immediately at the onset of a German attack and withdraw his Third Army Corps to the Linge to cover the southern flank of the Grebbe Line, leaving only a covering force behind. This Waal-Linge Position was to be reinforced with pillboxes; the budget for such structures was increased with a hundred million guilders.

French strategy

In addition to the Dutch Army and the German 18th Army, a third force, not all that much smaller than either, would operate on Dutch soil: the French 7th Army. It had its own objectives within the larger French strategy, and French planning had long considered the possibility of operations in Dutch territory. The coastal regions of Zealand and Holland were difficult to negotiate because of their many waterways. However, both the French and the Germans saw the possibility of a surprise flanking attack. For the Germans this would mean bypassing the Antwerp-Namur line. The Zealand Isles were considered to be strategically critical, as they are just opposite of the Thames estuary, so their capture would pose a special menace to the safety of England.

Rapid forces, whether for an offensive or defensive purpose, were needed to deny vital locations to the enemy. Long before the Germans did, the French had contemplated using airborne troops to achieve speedy attacks. As early as 1936 the French had commissioned the design of light airborne tanks, but these plans had been abandoned in 1940, as they possessed no cargo planes large enough to carry them. A naval division and an infantry division were earmarked to depart for Zealand to block the Western Scheldt against a German crossing. These would send forward forces over the Scheldt estuary into the Isles, supplied by overseas shipping.

French Commander in Chief General Maurice Gamelin feared the Dutch would be tempted into a quick capitulation or even an acceptance of German protection. He therefore reassigned the former French strategic reserve, the 7th Army, to operate in front of Antwerp to cover the river's eastern approaches in order to maintain a connection with the Fortress Holland further to the north. The force assigned to this task consisted of the 16th Army Corps, comprising the 9th Motorised Infantry Division (also possessing some tracked armoured vehicles) and the 4th Infantry Division; and the 1st Army Corps, consisting of the 25th Motorised Infantry Division and the 21st Infantry Division. This army was later reinforced by the 1st Mechanised Light Division, an armoured division of the French Cavalry and a first class powerful unit. Together with the two divisions in Zealand, seven French divisions were dedicated to the operation.

Although the French troops would have a higher proportion of motorised units than their German adversaries, in view of the respective distances to be covered, they could not hope to reach their assigned sector advancing in battle deployment before the enemy did. Their only prospect of beating the Germans to it lay in employing rail transport. This implied they would be vulnerable in the concentration phase, building up their forces near Breda. They needed the Dutch troops in the Peel-Raam Position to delay the Germans for a few extra days to allow a French deployment and entrenchment, but French rapid forces also would provide a security screen. These consisted of the reconnaissance units of the armoured and motorised divisions, equipped with the relatively well-armed Panhard 178 armoured car. These would be concentrated into two task forces named after their commander: the Groupe Beauchesne and the Groupe Lestoquoi.

German strategy and forces

During the many changes in the operational plans for Fall Gelb the idea of leaving the Fortress Holland alone, just as the Dutch hoped for, was at times considered. The first version of 19 October 1939 suggested the possibility of a full occupation if conditions were favourable. In the version of 29 October it was proposed to limit the transgression to a line south of Venlo. In the Holland-Weisung (Holland Directive) of 15 November it was decided to conquer the entire south, but in the north to advance no further than the Grebbe Line, and to occupy the Frisian Isles. Hermann Goering insisted on a full conquest as he needed the Dutch airfields against Britain; also he was afraid the Entente might reinforce Fortress Holland after a partial defeat and use the airfields to bomb German cities and troops. Another rationale for complete conquest was that as the fall of France itself could hardly be taken for granted, it was for political reasons seen as desirable to obtain a Dutch capitulation, because a defeat might well bring less hostile governments to power in Britain and France. A swift defeat would also free troops for other front sectors.

Though it was thus on 17 January 1940 decided to conquer the whole of the Netherlands, few units could be made available for this task. The main effort of Fall Gelb would be made in the centre, between Namur and Sedan, France. The attack at central Belgium was only a feint; and the attack at Fortress Holland only a side show of this feint. Although both the 6th and 18th Army were deployed at the Dutch border, the first, much larger, force would move south of Venlo to Belgium, leaving just the 18th Army under General Georg von Küchler to defeat the Dutch main force. Of all German armies to take part in the operation this was by far the weakest. It contained only four regular infantry divisions (the 207th, 227th, 254th and 256th Infantry Divisions), assisted by three reserve divisions (208th, 225th, and 526th Infantry Divisions) that would not take part in the fighting. Six of these divisions were "Third Wave" units only raised in August 1939 from territorial Landwehr units. They had few professional officers and had little fighting experience apart from those that were World War I veterans. Like the Dutch Army, most soldiers (88%) were insufficiently trained. The seventh division was the 526th Infantry Division, a pure security unit without any serious combat training. The German divisions, with a nominal strength of 17,807 men, were half as large as their Dutch counterparts and possessed twice their effective firepower, but the necessary numerical superiority for a successful offensive was simply lacking.

To remedy this, assorted odds and ends were used to reinforce 18th Army. The first of these was the only German cavalry division, aptly named 1st Kavalleriedivision. The mounted troops of this unit, accompanied by some infantry, were to occupy the weakly defended provinces east of the river IJssel and then try to cross the Afsluitdijk (Enclosure Dike). A simultaneous landing in Holland near Enkhuizen was to be attempted, using barges to be captured in the small port of Stavoren. As both efforts were unlikely to succeed, the mass of regular divisions was reinforced by the SS-Verfügungsdivision (including SS-Standarten Der Führer, Deutschland and Germania) and Leibstandarte Adolf Hitler, which would serve as assault infantry to breach the Dutch fortified positions. Still this added only 1 1/3 division to the equation.

Panzer I tank, now on display in Münster, Germany (2005)

To ensure a victory the Germans resorted to unconventional means. The Germans had trained two airborne/airlanding assault divisions. The first of these, the 7. Flieger-Division, consisted of paratroopers; the second, the 22nd Luftlande-Infanteriedivision, of airborne infantry. Initially the plan was that the main German assault was to take place in Flanders, and it was expected these troops would be used for a crossing attempt over the river Scheldt near Ghent. This operation was cancelled, so it was decided to use them to obtain an easy victory in the Netherlands. The airborne troops would on the first day attempt to secure the airfields around the Dutch seat of government, The Hague, and then capture that government, together with the Dutch High Command and the Dutch Queen Wilhelmina. German officers actually took lessons on how to address royalty on such occasions. The plan, Fall Festung, had been developed by Hitler personally, embellishing an earlier idea to let an envoy offer "armed protection of the Dutch neutrality", that is, to become a German protectorate. In the event this did not bring forth the desired immediate collapse, the bridges at Rotterdam, Dordrecht and Moerdijk would simultaneously be secured to allow a mechanised force to relieve the airborne troops from the south. This force was to be the German 9th Panzer Division. They were the only German armoured division having just two tank battalions, one understrength, in its single tank regiment; the total number of tanks in the group was 141. The intention was that they should exploit a breach in the Dutch lines created by the 254th and 256th Infantry Divisions, and join up with them, forming the XXVI. Armeekorps, on the Gennep – 's-Hertogenbosch axis. At the same time an offensive would be staged against the Grebbe Line in the east by the 207th and 227th Infantry Divisions, united to form X. Armeekorps, to engage the main bulk of the Dutch Field Army. The expectation was that in spite of the lack of numerical superiority, they would force the Dutch back to the east front of the Fortress Holland or beyond. If the Dutch did not capitulate on the first day, the Eighteenth Army expected to enter the Fortress Holland on the third day from the south and thereby ensure victory; there was no strict timetable for the total destruction of the Dutch forces. A peculiar aspect of the command structure was that the airborne attack was solely a Luftwaffe operation; the airborne forces would initially not be under operational command of the German Army. The attack on Rotterdam was ultimately to be an Army operation and considered by it as the Schwerpunkt (focal point) of the campaign in the Netherlands; 18th Army saw the air landings as primarily subservient to the XXVI. Armeekorps advance.

Of all operations of Fall Gelb this one most strongly embodied the concept of a Blitzkrieg as the term was then understood: a Strategischer Überfall or strategic assault. Also, like Fall Gelb as a whole, it involved a high risk strategy.

The Oster affair

The German population and troops generally disliked the idea of violating Dutch neutrality. The German propaganda therefore justified the invasion as a reaction to an Entente attempt to occupy the Low Countries. Some German officers had an aversion against the Nazi regime and were also uneasy about the invasion. One of them, Colonel Hans Oster, an Abwehr (German intelligence) officer, began in March 1939 to pass along information to his friend, the Dutch military attaché in Berlin Major Gijsbertus J. Sas. This information included the attack date of Fall Gelb. Sas informed the Allies via other military attachés. However, both the Dutch government and other nations became insensitive to the series of false alarms, as the date would be changed many times, because the attack was postponed to wait for favourable weather conditions. Sas' correct prediction of the date of the attack on Denmark and Norway went largely unheeded. Though he indicated a German armoured division would try to attack the Fortress Holland from North Brabant and that there was a plan to capture the Queen, the Dutch defensive strategy was not adapted and it was not understood these were elements of a larger scheme. On 4 May Sas again warned that an attack was imminent; this time it coincided with a warning from Pope Pius XII. When in the evening of 9 May Oster again phoned his friend saying just "Tomorrow, at dawn", the Dutch troops were put on alert. Oster was a leading figure of the German resistance from 1938 to 1943, and was one of those hanged after the 20 July 1944 bomb plot to assassinate Hilter.

The battle

10 May

The geography of the landing areas: at the coast is The Hague; Rotterdam is at n, Waalhaven at 9 and Dordrecht at 7; h indicates the Hollands Diep

On the morning of 10 May 1940 the Dutch awoke to the sound of aircraft engines roaring in the sky. Nazi Germany had commenced operation Fall Gelb and attacked the Netherlands, Belgium, France and Luxembourg, in the case of the Low Countries without a declaration of war given before hostilities; France was already at war.

In the night the Luftwaffe violated Dutch airspace. One wing, Kampfgeschwader 4, traversed it and then disappeared to the west, giving the Dutch the illusion that the operation was directed at England. But above the North Sea it turned to the east again to stage a surprise attack on the Dutch airfields, together with the other wings. Numerous Dutch aircraft were destroyed on the ground. The Dutch planes that were able to take off shot down thirteen German aircraft, but most were lost during the fighting or by emergency landings necessitated by the fact that the airforce facilities had come under ground attack.

Immediately after the bombardments, between 04:30 and 05:00 local time, paratroopers were landed near the airfields. Dutch anti-aircraft batteries shot down numerous Ju 52 transport planes of the Luftwaffe's Transportgruppen. German Ju 52 losses in the entire battle amounted to about 250, representing 50% of the fleet's strength.

Burning German Junkers Ju 52s at Ypenburg

The attack on The Hague ended in operational failure. The paratroopers were unable to capture the main airfield at Ypenburg in time for the airborne infantry to land safely in their Junkers. Though one armoured car had been damaged by a bomb, the other five Landsverks, assisted by machine gun emplacements, destroyed the eighteen Junkers of the first two waves, killing many occupants. When the airstrip was blocked by wrecks the remaining waves aborted the landing and tried to find alternatives, often putting down their teams in meadows or on the beach, thus dispersing the troops. The small auxiliary airfield of Ockenburg was only lightly defended, and fell at once to German attack. The airfield of Valkenburg was likewise quickly occupied, the morale of the defenders shaken by the bombardment. However, the landing strip was still under construction and the ground water level had not yet been lowered: planes landing there sank away in the soft soil. None of the airfields was thus capable of receiving substantial reinforcements. In the end the paratroopers occupied Ypenburg but failed to advance into The Hague, their route blocked by hastily assembled Dutch troops. Early in the afternoon they were dispersed by fire from three Dutch artillery batteries. Dutch batteries likewise drove away the German occupants from the other two fields, the remnant airborne troops taking refuge in nearby villages and mansions.

German losses on Waalhaven airfield were limited

The attack on Rotterdam was much more successful. Twelve Heinkel He 59 seaplanes, crowded with two platoons of troops, landed in the heart of the city and unloaded assault teams that conquered the Willemsbrug, a bridge over the Nieuwe Maas, to occupy a bridgehead. At the same time the military airfield of Waalhaven, positioned south of the city on the island of IJsselmonde, was attacked by airborne forces. Here an infantry battalion was stationed, but so close to the airfield that the paratroopers landed near its positions. A confused fight followed. The first wave of Junkers suffered no losses and the transports continued to land. In the end the Dutch defenders were overwhelmed. The German troops, steadily growing in numbers, began to move to the east to occupy IJsselmonde and eventually made contact with the paratroopers tasked with occupying the vital bridge at Dordrecht. Although the Royal Dutch Navy intervened — the torpedo boats Z5 and TM 51 attacked the Willemsbrug and later the destroyer HNLMS Van Galen sailed up the Nieuwe Waterweg to bombard the airfield at short range — this only resulted in the Van Galen foundering after being bombed. A plan to commit the gunboats HNLMS Flores and HNLMS Johan Maurits van Nassau was therefore abandoned. At the Island of Dordrecht the Dordrecht bridge was captured but in the city itself the garrison held out. The long Moerdijk bridges over the broad Hollands Diep estuary connecting the island to North Brabant province were captured and a bridgehead fortified on the southern side.

German landings in Rotterdam

The Germans, executing a plan approved by Hitler, — though not contrived by him personally — tried to capture the IJssel and Maas bridges intact, using commando teams of Brandenburgers that began to infiltrate over the Dutch border ahead of the main advance, with some troops arriving on the evening of 9 May. During the night of 10 May they approached the bridges: several teams had a few men dressed as Dutch military police pretending to bring in a group of German prisoners, to fool the Dutch detonation teams. Some of these "military policemen" were real Dutchmen, members of the Nationaal-Socialistische Beweging, the Dutch nazi party. Most of these attempts failed and the bridges were blown, on two occasions with Brandenburgers and all. The main exception was the Gennep railway bridge. Immediately an armoured train crossed it followed by a troop train, both driving right through the Peel-Raam Position at Mill and unloading an infantry battalion behind the defence line.

The Dutch released reports of German soldiers in disguise to the international news agencies. This caused a fifth column scare, especially in Belgium and France. However, unlike the situation later on in those two countries, in the Netherlands there was no mass exodus of civilian refugees, clogging the roads. Generally German soldiers behaved in a civilised manner towards the Dutch population, forming neat queues at the shops to buy goods rationed in Germany, such as chocolate.

After the generally failed assaults on the bridges, the German divisions began crossing attempts over the rivers IJssel and Maas. The first waves typically were destroyed, due to insufficient preparatory fire on the pillboxes. At most places a secondary bombardment destroyed the pillboxes and the infantry divisions crossed the river after building pontoon bridges; but at some, as Venlo, the attempt was aborted. At Arnhem, Leibstandarte Der Fuehrer led the assault and that day advanced to the Grebbe Line, followed by 207. Infanteriedivision.

Despite the destruction of the Wilhelminabrug, German troops passed this vital traffic hub relatively quickly. Photo taken 10 May 1940 in Maastricht.

Even before the armoured train arrived, 3rd Army Corps had already been planned to be withdrawn from behind the Peel-Raam Position, taking with it all the artillery apart from 36 8 Staal pieces. Each of its six regiments was to leave a battalion behind to serve as a covering force, together with fourteen "border battalions". The group was called the "Peel Division". This withdrawal was originally planned for the first night after the invasion, under cover of darkness, but due to the rapid German advance an immediate retreat was ordered at 06:45, to avoid 3rd Army Corps becoming entangled with enemy troops. The corps joined "Brigade G", six battalions already occupying the Waal-Linge line, and was thus brought up to strength again. It would see no further fighting.

The Light Division, based at Vught, was the only manoeuvre force the Dutch Army possessed. Its planned withdrawal had been similarly executed a day early. Its regiments had biked over the Maas and Waal bridges and then turned left through the Alblasserwaard when it was decided in the afternoon to let it counterattack the German airborne landing on IJsselmonde. It reached the Noord, the river separating the Alblasserwaard from IJsselmonde, in the evening. There they discovered that the sector near the only bridge, built in 1939, was not strongly occupied by the airborne troops, as the Germans simply had not known of its existence because of outdated maps. It was decided to postpone a crossing until the next day, to gather sufficient forces. No attempt was made to establish a bridgehead.

Meanwhile, on the evening of the 10th, around 22:00, French reconnaissance elements using Panhard 178 armoured cars had started to arrive at the Dutch border, forming a vanguard for the French Mechanised Light Division. This division operated, with the 25e DIM on its left, on the northern flank of the French 7th Army; its mission was to ensure contact between the Vesting Holland and Antwerp. Attempts to coordinate the French advance with Colonel Leonard Johannes Schmidt, the military commander of the Dutch troops on Noord-Brabant, were largely unsuccessful as, apart from the fact he could not be reached that day, Dutch defences there were already collapsing. At Mill, 256. Infanteriedivision at first could not exploit the opportunity offered by having a battalion in the back of the defenders because it failed to locate it. When a first attack by forward elements had been repulsed, a full assault at the Main Defense Line was initially postponed to the next day because most artillery had not yet passed the single pontoon bridge over the Meuse, which had caused a traffic jam after having been damaged by an incident. In the early evening in a sudden change of plans it was decided to attack even though artillery support was absent apart from one 105 mm battery. An unrequested Stuka attack that also happened to hit the Mill sector just prior to the advance routed some Dutch defenders, creating a weak section in the line from which the Dutch troops were dislodged. Though the Germans were slow to exploit the breakthrough, Colonel Schmidt at 20:30 ordered the Peel-Raam Position to be abandoned and his troops to fall back to the west improvising a new line at the Zuid-Willemsvaart canal .

In the North, by the end of the day, 1. Kavalleriedivision had reached the line Meppel – Groningen, delayed by logistical problems and Dutch demolition teams blowing up 236 bridges. Dutch troop strength in that area was weak.

In the extreme south, the six border battalions in the province of Limburg only slightly delayed the advance of the German Sixth Army; before noon the area had been overrun and the strategic city of Maastricht had surrendered, opening the way for the German feint offensive into Central Belgium. The Germans however, failed to capture the main bridge intact, forcing them to delay the crossing by the 4th Panzer Division until the next day.

11 May

On 11 May the Dutch commander General Winkelman was faced with two priorities. First of all he wanted to eliminate the German airborne troops. Though the strategic assault had failed, he feared a further enemy build-up via Waalhaven and saw the German possession of the Moerdijk bridges as a serious impediment to the movement of allied reinforcements to the Fortress Holland. The second priority was closely related to the first: enabling the French army to build up a strong defensive line in North Brabant, to connect the Fortress Holland with the Allied main force in Belgium. As he had withdrawn most of his troops from the area, Winkelman had only limited means available to influence this process, largely leaving this task to local commanders.

In both respects, little was achieved this day. The planned counterattack by the Light Division against the airborne troops on IJsselmonde failed. In the nick of time the bridge over the river Noord had been prepared for defence by the German paratroopers, and it proved impossible to force it. Several attempts to cross the river by boats only managed to establish some isolated bridgeheads, and at 10:15, the Light Division was given permission to break off the crossing at this point and ordered to shift its axis of attack by reinforcing the Dutch troops on the Island of Dordrecht, where it arrived that night. After having cleared the Island of Dordrecht of enemy troops the division was to advance into IJsselmonde over the Dordrecht bridge in order to reach Rotterdam.

Earlier during the day, two attempts were made by Dutch battalions to carry out an attack against the western flank of the German perimeter. The first battalion, withdrawn from the Belgian border, partly crossed the Oude Maas at two points (Oud-Beijerland and Puttershoek) and tried to storm the bridge at Barendrecht into IJsselmonde; the second battalion, taken from the Fortress Holland forces positioned at the Hoekse Waard, had already crossed the Dordtse Kil into the Island of Dordrecht the previous day, using the ferry at Wieldrecht and now tried to expand its bridgehead. Although its crossings were successful, the advance of the first battalion was executed only hesitantly; the troops were surprised by German counterattacks and dispersed. The second battalion was likewise surprised with many men being taken prisoner. In the afternoon a French reconnaissance unit, the 5e Groupe de Reconnaissance de Division d'Infanterie, with the assistance of another Dutch border battalion attempted an attack on the southern Moerdijk bridgehead, but the armoured cars of 6e Cuirassiers with which it was reinforced were heavily bombed by German Stukas and had to retreat.

General der Fallschirmjäger Kurt Student

In Rotterdam, though reinforced by an infantry regiment, the Dutch failed to completely dislodge the German airborne troops from their bridgehead on the northern bank of the Maas. Despite permission by General Kurt Student, the German commander in Rotterdam refused to evacuate this bridgehead and the few German defenders held fast in a single office building, protected by a canal in front of them and covered by fire from the south bank. The two remaining Dutch bombers failed to destroy the Willemsbrug. The German forces involved in the attack of the previous day on The Hague also held out, none of the attempts to eliminate the isolated groups of in total about 1600 paratroopers and airlanded forces met with success.

In North Brabant, the situation swiftly deteriorated. The French commanders of the 7th Army had expected that Dutch resistance at the Meuse and the Peel-Raam Position, by a force about five divisions strong, would have gained them at least four days to build up a defensive line near Breda. They were unpleasantly surprised to learn that the best three divisions had been moved to the north and that the remaining forces were already in full retreat. The withdrawal of the Peel Division from the Peel-Raam Position to the Zuid-Willemsvaart, a canal some 10至30公里（6.2至18.6英里） to the west, meant leaving behind their well-entrenched positions and the little artillery available in exchange for a totally unprepared line. Moreover, the eastern bank of the canal was higher than the western bank, providing excellent cover for the attackers. Finally, the order to withdraw never reached the troops at Mill; this caused one sector of the canal, near Heeswijk, to be left undefended; as this sector contained a bridge which was not demolished, the Germans were effortlessly able to cross the canal around 13:00. A second crossing at Erp, against opposition, led to a general collapse of the line. By the end of the 11th, the Germans had crossed the Zuid-Willemsvaart at most places and the Peel Division had largely disintegrated. Plans by Colonel Schmidt to concentrate his forces on the line Tilburg-'s-Hertogenbosch thus came to nothing. As the French refused to advance further to the northeast than Tilburg, apart from some reconnoitering armoured cars that went as far as Berlicum, this created a dangerous gap. Winkelman, sensitive to the general Dutch weakness in the region, requested the British government to sent an Army Corps to reinforce allied positions in the area and bomb Waalhaven airfield.

All the efforts in the south were made on the assumption the Grebbe Line would be able to beat off attacks on its own; its reserves had even been partly shifted to the counterattack against the airborne forces. However, there were some indications that a problem was developing in this sector. Motorised elements of SS Standarte "Der Fuehrer", preceding 207. Infanteriedivision, had reached the southernmost part of the Grebbe Line, in front of the Grebbeberg, on the evening of the 10th. This Main Defense Line sector had no inundations in front of it and had therefore been chosen as the main attack axis of the division. It was protected by a line of outposts (voorpostenlinie), manned by two companies of infantry. At about half past three in the morning of the 11th, German artillery started shelling the outposts, followed at dawn by an attack by two battalions of Der Fuehrer. As the German shelling had cut the telephone lines, no artillery support could be requested by the Dutch defenders. Defence was further hampered by the fact that the terrain had not yet been cleared of vegetation, which offered good cover for the attackers. At noon a breakthrough was accomplished at the extreme north of the outpost line and the Dutch positions were then slowly rolled up from behind. The outnumbered and inferiorly armed companies resisted as well as they could, but by evening, all outposts were in German hands. The commander of 2nd Army Corps, Major-General Jacob Harberts, failed to react adequately. He did not realise that motorised SS troops had been involved in the attack, and thought that the outposts had been surrendered to a small probing German force through the cowardice of the defenders. He ordered a night counterattack by the single reserve battalion of 4th Division. This attack was abandoned; on its approach the battalion was fired upon by Dutch troops manning the main line that had not been notified of its approach, leading to much confusion, and an engineer bridge necessary to cross the Grift rivulet failed to be brought forward in time. However, heavy preparatory Dutch artillery fire had the unintended effect of causing the Germans to abandon their plans for a night attack.

Meanwhile in the North, 1. Kavalleriedivision advanced through the province of Friesland towards the final Dutch fall-back line, the Wonsstelling, reaching Sneek in the evening. Most Dutch troops had been evacuated from the north over the Enclosure Dike.

12 May

參見：Battle of the Grebbeberg

On the morning of 12 May General Winkelman remained moderately optimistic. He still assumed a firm defence line could eventually be established in North Brabant with the help of the French and expected good progress could be made in eliminating the airborne forces, while not being aware of any special danger to the Grebbe Line. During the day his hopes would be dashed.

In the two previous days, 9. Panzerdivision had seen no action. It crossed the Meuse in the early morning of 11 May and during that day was unable to advance quickly over roads that were congested by supply trains of the infantry divisions. As the Dutch front had dissolved, the armoured division now decided to link up with the airborne troops. In this it would not be hindered by the French forces. Because the German 6th Army was threatening its right flank and there was no time to prepare, Gamelin ordered the 2e Brigade Légère Mecanique, part of 1 Division Légère Mécanique, 7th Army to withdraw to the south. They arrived at Tilburg. The 25e Division d'Infanterie Mecanisée was positioned at Breda, and told to progress no further to the north than the river Mark. As the initial order to occupy the Geertruidenberg sector had not been followed up on, the route to the Moerdijk bridges was not blocked. The German armoured division would not be engaged by its stronger French counterpart. The reconnaissance elements of the 9th Panzer Division effectively exploited this opportunity: at dawn they attacked north of Tilburg, near Loon op Zand. Colonel Schmidt was taken prisoner; the Dutch troops in the province lost all unified command. At 16:45 the German armoured cars penetrated forty kilometres to the west and reached the southern Moerdijk bridgehead, cutting off the Fortress Holland from the Allied main force. The northern part of that force would not long remain in the region: at 13:35 Gamelin ordered a complete withdrawal to Antwerp of all French troops in North-Brabant, who would now limit themselves to rear-guard actions.

The Light Division tried to systematically reconquer the Island of Dordrecht by advancing on a broad front, using four battalions with little artillery support. On its left flank, where there was almost no enemy presence, the advance went according to plan. The battalion on the right flank ran into an attacking German force of battalion strength that had been ordered by General Student to circle around the outskirts of the city to relieve the pressure being placed on his troops holding the Dort bridge. In confused street fighting the German troops gained the upper hand and drove the battalion back; the other units then halted their advance around noon. Though higher command soon ordered a better concentration of forces instead of some mopping-up action, due to a lack of clear lines of command, no subsequent attack materialised that day.

In Rotterdam and around The Hague little was done against the paratroopers. Most Dutch commanders, still afraid of a presumed Fifth Column, limited themselves to security measures; they had been ordered not to stage any attacks above company level.

The Grebbeberg seen from the south; the slopes facing the attackers in the east were more gradual (2005)

While the situation in the south was becoming critical, in the east the Germans made a successful effort in dislodging the Dutch defenders on the Grebbeberg. After preparatory artillery bombardment in the morning, at around noon a battalion of Der Fuehrer attacked an eight hundred metres wide sector of the main line, occupied by a Dutch company. Exploiting the many dead angles in the Dutch field of fire, it soon breached the Dutch positions, which had little depth. A second German battalion then expanded the breach to the north. Dutch artillery, though equal in strength to the German, failed to bring sufficient fire on the enemy concentration of infantry, largely limiting itself to interdiction. Eight hundred metres to the west was a Stop Line, a continuous trench system from which the defenders were supposed to wage an active defence, staging local counterattacks. Due to a lack of numbers, training, and heavy weapons the attacks failed against the well-trained SS troops. By the evening the Germans had brought the heavily forested area between the two lines under their control. Spotting a weak point, one of the SS battalion commanders, Obersturmbannführer Hilmar Wäckerle, suddenly attacked with a hastily assembled force of about company strength using infiltration tactics broke through the Stop Line, quickly advancing a mile to the west until being halted by a fall-back line along the Rhenen railroad. The breakthrough caused a panic among the defenders, who largely abandoned the Stop Line; but as Wäckerle had had no time to coordinate his action with other units, it was not further exploited. Order was restored at the Stop Line and the SS company became isolated and surrounded. The general German advance caused the main line to be abandoned for over two miles to the north because the troops there feared an attack from behind.

It had been well understood by the Dutch that the forces occupying the Grebbe Line would not be sufficiently strong to repel all attacks by themselves; they were intended to delay an offensive long enough for reserves to reinforce them. Due to the failure the previous day to understand that the German main assault was imminent, these reserves would not arrive in time to intervene in the fight at the defence zone between the two trench systems. This was all the more serious as the Stop Line had no depth and lacked large shelters to accommodate enough troops to stage a strong frontal counterattack. In the late evening it was decided to execute a flank attack from the north the next day.

In the North, the Wons Position formed a bridgehead at the eastern end of the Enclosure Dike; it had a long perimeter of about nine kilometres to envelop enough land to receive a large number of retreating troops without making them too vulnerable to air attack. On 12 May units with a combined strength of only two battalions were still present, so the line was weakly held. This was exploited by the first German unit to arrive, the single bicycle battalion of 1. Kavalleriedivision. At noon they quickly penetrated the line in a concentrated attack, forcing the defenders to withdraw to the Enclosure Dike. For some the German advance cut off their escape route by land; they sailed away from the small port of Makkum, taking the last remaining vessels on the eastern side of Lake IJssel. This denied the Germans any craft for a crossing attempt, which plan was now abandoned.

Burnt-out Shell Oil reservoirs

In the afternoon General Winkelman received information about armoured forces advancing in the Langstraat region, on the road between 's-Hertogenbosch and the Moerdijk bridges. He still fostered hopes that those forces were French, but the announcement by Radio Bremen at 23:00 that German tanks had linked up with the paratroopers ended those hopes. He ordered the artillery batteries in the Hoekse Waard to try and destroy the Moerdijk bridges and sent a special engineering team to Rotterdam to blow up the Willemsbrug. Pessimistic about the general situation at this point, he also ordered the vast strategic oil reserves of Royal Dutch Shell at Pernis to be set on fire. Having been informed by Winkelman of his concerns earlier in the afternoon, the Dutch government asked Winston Churchill for three British divisions to turn the tide. The new prime minister answered that he simply did not have any reserves; however, three British torpedo boats were sent to Lake IJssel.

The German command was very satisfied with the day's events. It had been feared that the third day of the operation might become a "crisis day". Near Breda the XXVI Armeekorps had to overcome the resistance of several French divisions. The Germans were also concerned that they may face some Belgian or even British divisions (but in fact it turned out they did not). Therefore von Bock requested reinforcememts for this effort from another Army Corps. When this was denied by chief of staff Franz Halder, he arranged the formation of an extra Army Corps headquarters to direct the complex strategic situation of simultaneously fighting the Allies and advancing into the Fortress Holland over the Moerdijk bridges. As on 12 May no actual crisis seemed to materialise, von Bock decided that XXVI Armeekorps would be responsible for pursuing the French south towards Antwerp, while some forces would be directed by the new headquarters, Generalkommando XXXIX under command of General Rudolf Schmidt, to advance north with 254. Infanteriedivision, most of 9. Panzerdivision, and SS Leibstandarte Adolf Hitler.

13 May

In the early morning of 13 May General Winkelman advised the Dutch government that he considered the general situation to be critical. On land the Dutch had been cut off from the Allied front and it had become clear no major Allied landings were to be expected to reinforce the Fortress Holland by sea; without such support there was no prospect of a prolonged successful resistance. German tanks might quickly pass through Rotterdam; Winkelman ordered all available antitank-guns to be placed in a perimeter around The Hague, to protect the seat of government. However, an immediate collapse of the Dutch defences might have been prevented if the planned counterattacks could seal off the southern front near Dordrecht and restore the eastern line at the Grebbeberg. Therefore the cabinet decided to continue the fight for the time being, giving the general the mandate to surrender the Army when he saw fit and the instruction to avoid unnecessary sacrifices. Nevertheless it was also deemed essential that Queen Wilhelmina was to be brought to safety; she departed around noon from Hoek van Holland, where a British Irish Guards battalion was present, on HMS Hereward, a British destroyer, and when sea mines made it too dangerous to try to reach Zealand, she went to England. The previous evening Crown Princess Juliana, together with her husband Prince Bernhard and their children, had departed from IJmuiden on HMS Codrington for Harwich. As the Queen constitutionally was part of the government, her departure confronted the cabinet with the choice whether to follow her or remain. After heated discussions it was decided to leave: the ministers sailed at 17:20 from Hoek van Holland on HMS Windsor to form a government in exile in London, having conferred all governmental authority over the homeland to Winkelman.

While two tank companies of 9. Panzerdivision remained with XXVI Armeekorps to pursue the withdrawing French, the other four began to cross the Moerdijk traffic bridge at 05:20. The Dutch made some attempts to indirectly block their advance. At around 06:00 the last operational medium bomber, a Fokker T. V, dropped two bombs on the bridge; one hit a bridge pillar but failed to explode; the bomber was shot down. Dutch batteries in the Hoekse Waard, despite dive bomber attacks, tried to destroy the bridge by artillery fire, but the massive structure was only slightly damaged. An effort to inundate the Island of Dordrecht failed, as the inlet sluices were too small.

The Light Division tried to cut the German corridor by advancing to the west and linking up with a small ferry bridgehead over the Dortse Kil. However, two of the four battalions available were decimated in a failed effort to recapture the suburbs of Dordrecht; when the other two battalions approached the main road, they were met head on by a few dozen German tanks. The vanguard of the Dutch troops, not having been informed of their presence, mistook the red air recognition cloths strapped on their tops for orange flags French vehicles might use to indicate their friendly intentions — orange being seen by the Dutch as their national colour — and ran towards the vehicles to welcome them, only understanding their error when they were gunned down. The battalions, already wavering because of a bombardment, fled to the east; a catastrophe was prevented by 47mm and 75 mm batteries destroying with direct armor piercing fire two Panzer IIs, after which the remainder of the German tanks fell back. The Light Division then successfully completed an ordered withdrawal to the Alblasserwaard at around 13:00. In the early afternoon eight tanks reduced the ferry bridgehead. A tank company also tried to capture the old inner city of Dordrecht without infantry support, audaciously breaching barricades, but was beaten back in heavy street fighting after two Panzer IIs were destroyed and three other tanks heavily damaged. All Dutch troops were withdrawn from the island in the night.

German armoured forces advanced north over the Dordrecht bridge into IJsselmonde island. Four tanks, three Panzer IIs and a Panzer III of the staff platoon of the 1st Tank Battalion, stormed the Barendrecht bridge into the Hoekse Waard, but all of them were lost to a single 47 mm antitank-gun. Though the Germans did not follow up their attack, this area was abandoned by the Dutch troops.

The Willemsbrug shortly after its opening in 1878, as seen from Noordereiland. A new bridge was completed nearby in 1981, and this one was demolished.

In Rotterdam a last attempt was made to blow up the Willemsbrug. The commander of the 2nd Battalion Irish Guards in Hoek van Holland refused to participate in the attempt as being outside the scope of his orders. Two Dutch companies, one of them of Dutch marines, stormed the bridgehead. The bridge was reached and the remaining fifty German defenders in the building in front of it were on the point of surrender when the attack was abandoned because of heavy flanking fire from the other side of the river.

In the North, the commander of 1. Kavalleriedivision, Major General Kurt Feldt, faced the unenviable task of having to advance over the Enclosure Dike because of a lack of ships. The advance was blocked by the Kornwerderzand Position, which protected a major sluice complex regulating the water level of Lake IJssel, which had to be sufficiently high to allow many Fortress Holland inundations to be maintained. The main fortifications contained 55 mm antitank-guns. Long channel piers projected in front of and behind the sluices, on both the right and left; on these pillboxes had been built which could place a heavy enfilading fire on the dam, which did not provide the slightest cover for any attacker. On 13 May the position was reinforced by a 20 mm anti aircraft battery. It had been Feldt's intention to first destroy the position by a battery of siege mortars, but the train transporting it had been blocked on 10 May by a blown railway bridge at Winschoten. Several air attacks on 13 May had little effect; in the late afternoon five bicycle sections tried to approach the main bunker complex under cover of an artillery bombardment, but soon fled after being fired upon; the first was pinned down and could only retreat under cover of darkness, leaving behind some dead.

In the East the Germans discovered a dry approach route through the inundations near Scherpenzeel, so the 227. Infanteriedivision of X. Armeekorps tried to overcome the resistance at the Grebbe Line. The line was defended by the Dutch 2nd Infantry Division. Two regiments were to attack simultaneously, in adjacent sectors. However, when the regiment on the right, 366. Infanterieregiment, was in position for the attack, the regiment on the left, 412. Infanterieregiment, became delayed by flanking fire from Dutch outposts, the position of which had not been correctly determined. It allowed itself to get involved in fragmented firefights; though eventually the reserve regiment was brought forward, little progress was made against the outpost line. Meanwhile, the waiting 366. Infanterieregiment was pounded by concentrated Dutch artillery fire and had to withdraw, resulting in a complete failure of the attack by 227 Infanteriedivision.

Junkers Ju 87 Stuka

South towards the Grebbeberg, during the evening and night the Dutch had assembled about a dozen battalions for a counterattack to retake the main line. These forces consisted of reserve battalions of several army corps, divisions and brigades, and the independent Brigade B, which had been freed when the Main Defence Line in the Land van Maas en Waal had been abandoned as part of the withdrawal of III Army Corps from North Brabant. However, not all of these units would be concentrated into a single effort. Some battalions had been fed immediately into the battle at the Stop Line, and others were kept in reserve, mainly behind the fall-back line near the Rhenen railroad. Four were to be used, under command of Brigade B, for the flanking attack from the north. This attack was delayed for several hours; when it finally started late in the morning of 13 May, it ran right into a comparable advance by two battalions of Der Fuehrer; this brigade, unaware of Dutch intentions, had shifted its attack axis to the north to roll up the Grebbe Line from behind. A confused encounter fight followed in which the vanguard of the Dutch troops, poorly supported by their artillery, began to give way at around 12:30 to the encroaching SS troops. Soon this resulted in a general withdrawal of the brigade, which turned into a rout when the Grebbeberg area was bombed by 27 Ju 87 Stukas that started at 13:30.

Meanwhile, at the Grebbeberg itself, 207. Infanteriedivision was committed to battle for the first time when two battalions of its 322. Infanterieregiment attacked the Stop Line. The first wave of German attackers was largely beaten off with serious losses, but a second wave managed to fragment the trench line, which then was taken after heavy fighting. The regiment next proceeded to mop up the area to the west, delayed by resistance by several Dutch command posts. They withdrew in the late afternoon, just as the SS battalions further north shifted to a more western position to redeploy for a renewed attack. Their intention was to take the Rhenen fall-back line and the village of Achterberg. However, these preparations would be prove to be superfluous: the Dutch had already disappeared.

The same Stuka bombardment that made Brigade B rout also broke the morale of the reserves at Rhenen. In the morning these troops had shown severe discipline problems, with units disintegrating and leaving the battlefield because of German interdiction fire. In the late afternoon most of 4th Infantry Division was fleeing westwards. A 8 km（5.0 mi） wide gap appeared in the line. The Germans planned to shift two regiments of 3rd Army Corps to this part of the line. The Dutch command suffered such a loss of control that attempts to plug the line had to be abandoned. Fearing that otherwise they would be encircled, at 20:30 Van Voorst tot Voorst ordered that the three Army Corps to abandon both the Grebbe Line and the Waal-Linge Position immediately and to retreat during the night to the East Front of Fortress Holland at the New Holland Water Line. The Germans did not at once exploit their success; only around 21:00 had it become apparent to them that the gap even existed, when the renewed advance had met no enemy resistance.

14 May

Dutch situation just before the Bombing of Rotterdam. Legend:

  Location of the Dutch defence lines and area within Dutch troops are present

  Heavy Dutch defence line against armoured vehicles

  Dutch defences in Zeeland

  Belgian defence line

  French defences in the Netherlands

  Position of German troops as well as areas under German control

Despite his pessimism expressed to the Dutch government and the mandate he had been given to surrender the Army, General Winkelman awaited the outcome of events, avoiding actually capitulating until it was absolutely necessary. In this he was perhaps motivated by a desire to engage the opposing German troops for as long as possible, to assist the Allied war effort. In the early morning of 14 May, though the situation remained critical, a certain calm was evident in the Dutch Headquarters.

In the North, German artillery bombardment of the Kornwerderzand Position began at 09:00. However, the German batteries were forced to move away after being surprised by counterfire from the 15 cm. aft cannon of Hr. Ms. Johan Maurits van Nassau that had sailed into the Wadden Sea. Feldt now decided to land on the coast of North-Holland. A few barges were found; one barge foundered and the remainder lost their way. The crossing was actually executed only after the capitulation. On 14 May Winkelman gave orders to occupy the Amsterdam Position, the North Front of the Fortress Holland, but only weak forces were available.

In the East, under cover of ground fog the field army successfully withdrew from the Grebbe Line to the East Front without being bombed, and disengaged from the gradually pursuing enemy troops. The new position had some severe drawbacks: the inundations were mostly not yet ready and the earthworks and berms needed because trenches would be flooded in the peat soil had not yet been constructed, so defences had to be improvised to accommodate a large number of troops.

On IJsselmonde the German forces prepared to cross the Meuze in Rotterdam, which was defended by about eight Dutch battalions. Crossings would be attempted in two sectors. The main attack would take place in the centre of the city, with the German 9th Panzer Division advancing over the Willemsbrug. Then Adolf Hitler would cross to operate on its immediate left and east of Rotterdam a battalion of the 16th Infantry Regimentt of the 22nd Light Division would cross on boats. These auxiliary attacks might prevent a concentration of Dutch forces, blocking the 9th Panzer Division's advance through a densely built up urban area intersected by canals. In view of these conditions and the limited means available, there was a major emphasis on air support. On 13 May, Von Küchler, fearing that the British might reinforce the Fortress Holland, had instructed Schmidt: "Resistance in Rotterdam should be broken with all means, if necessary threaten with and carry out the annihilation [Vernichtung] of the city". In this he was to be supported by the highest command level as Hitler would state in Führer-Weisung Nr. 11 (Führer-Directive #11): "On the northern wing the power of the Army of Holland to resist has proven stronger than had been assumed. Political as well as military grounds demand to quickly break this resistance. (...) Furthermore the speedy conquest of the Fortress Holland is to be facilitated through a deliberate weakening of the [air] power operated by Sixth Army". Kampfgeschwader 54, using Heinkel He-111 bombers, was therefore shifted from Sixth to Eighteenth Army.

Dutch negotiator, carrying white flag, moves toward the German positions on the Noordereiland. May 14, 1940.

Generals Kurt Student and Schmidt desired a limited attack to temporarily paralyse the defences, allowing the tanks to break out of the bridgehead; severe urban destruction was to be avoided as it would only hamper their advance. However, Luftwaffe commander Hermann Goering, worried about the fate of his surrounded airborne troops, hoped to force an immediate Dutch capitulation by a much more extensive bombardment. His head of operations, General Otto Hoffman von Waldau, described this option as a "radical solution" [Radikallösung]. Despite misgivings by Albert Kesselring about its scope and necessity, at 11:45 ninety Heinkels took off for a carpet bombing of the inner city of Rotterdam.

German troops advance through a destroyed section of Rotterdam

At 09:00 a German messenger crossed the Willemsbrug to bring an ultimatum from Schmidt to Colonel Pieter Scharroo, the Dutch commander of Rotterdam, demanding a capitulation of the city; if a positive answer had not been received within two hours the "severest means of annihilation" would be employed. Scharroo did not receive the message until 10:30. Not feeling inclined to surrender regardless, he asked Winkelman for orders; the latter, hearing that the document had not been signed nor contained the name of the sender, instructed him to send a Dutch envoy to clarify matters and gain time. At 12:15 a Dutch captain handed this request to von Choltitz. On the return of the German envoy at 12:00, Schmidt sent a radio message that the bombardment had to be postponed because negotiations had started. At around 13:20 the Dutch envoy received a second ultimatum, now signed by Schmidt, with a new expiry time of 16:20. Meanwhile, two squadrons of Heinkels arrived, not having received any recall orders. The Germans later explained that the aircraft had already had their tow aerials pulled. Schmidt ordered red flares to be fired to signal that the bombardment was to be broken off, but only the squadron making the bomb run from the southwest abandoned its attack, after their first three planes had dropped their bombs. The other 54 Heinkels, approaching from the east, continued to drop a grand total of 1308 bombs, destroying the inner city and killing 814 civilians. The ensuing fires destroyed about 24,000 houses, making almost 80,000 inhabitants homeless. At 15:50 Scharroo capitulated to Schmidt in person. Meanwhile Goering had ordered a second bombardment of the city, to be carried out unless a message was received that the whole of Rotterdam was occupied. A group of Heinkels had already left; when Schmidt heard this at 17:15 he hastily sent an uncoded message claiming the city was taken, although this had yet to take place. The bombers were recalled just in time.

The surrender of the Dutch Army

The phases of the Dutch occupation

Winkelman at first intended to continue the fight, even though Rotterdam had capitulated and German forces from there might now advance into the heart of the Fortress Holland. The possibility of terror bombings was considered before the invasion and had not been seen as grounds for immediate capitulation; provisions had been made for the continuation of effective government even after widespread urban destruction. The perimeter around The Hague might still ward off an armoured attack and the New Holland Water Line had some defensive capability; though it could be attacked from behind, it would take the Germans some time to deploy their forces in the difficult polder landscape. However, he soon received a message from Colonel Cuno Eduard Willem baron van Voorst tot Voorst, the commander of the city of Utrecht, that the Germans demanded its surrender; leaflets were dropped by propaganda planes announcing that only unconditional surrender could "spare it the fate of Warsaw". Winkelman concluded that it apparently had become the German policy to devastate any city offering any resistance; since his mandate to avoid unnecessary suffering and the Dutch military position was hopeless he decided to surrender. All units were ordered at 16:50 by Telex to first destroy their weapons and then offer their surrender to German units. At 17:20 the German envoy in The Hague was informed. At 19:00 Winkelman gave a radio speech informing the Dutch people. This was also how the German command became aware the Dutch had surrendered; the Dutch troops had generally disengaged from the enemy and had not yet made contact.

Winkelman, in the center, leaves the school building in which the negotiations took place

Winkelman acted both in his capacity of commander of the Dutch Army and of chief executive of the homeland. This created a somewhat ambiguous situation. On the morning of 14 May the commander of the Royal Dutch Navy, Vice-Admiral Johannes Furstner, had left the country to continue the fight; Dutch naval vessels were generally not included in the surrender. Eight ships and four unfinished hulks had already departed, some smaller vessels were sunk, and nine others sailed for England in the evening of 14 May. The Hr. Ms. Johan Maurits van Nassau was sunk by German bombers while crossing. The commander at the main Dutch naval port of Den Helder, Rear-Admiral Hoyte Jolles, concluded that his base, with a naval garrison of 10,000, its own air service, and extensive land defences, should continue to resist. Only with some difficulty did Winkelman convince him to obey the surrender order. Large parts of the Dutch Army were also reluctant to believe or accept the surrender, especially those units that hardly had seen any fighting, such as 3rd and 4th Army Corps and Brigade A.

At 05:00 on 15 May a German messenger reached The Hague, inviting Winkelman to Rijsoord for a meeting with von Küchler to negotiate the articles of a written capitulation document. Both quickly agreed on most conditions, Winkelman declaring to have surrendered army, naval and air forces. When von Küchler demanded that pilots still fighting for the allies should be treated as francs-tireurs (guerilla fighters outside the laws of war), Winkelman's refusal made it clear to the Germans that only the armed forces in the homeland would capitulate, not the country itself. On other points a swift agreement was reached and the document was signed at 10:15

The fighting in Zealand

The province of Zealand was exempt from the surrender; fighting continued there in a common allied effort with French troops. The Dutch forces in the province comprised eight full battalions of army and naval troops. They were commanded by Rear-Admiral Hendrik Jan van der Stad, who, though a naval officer, had been directly subordinated to Winkelman. The area was under naval command because of the predominance of the naval port of Vlissingen on the island of Walcheren which controlled the access to Antwerp via to the Western Scheldt. The northern islands of the province were almost undefended apart from some platoons and the defence of Zeeuws-Vlaanderen. The Dutch part of Flanders was largely left to the Allies. The main Dutch army forces would be concentrated in Zuid-Beveland, the peninsula east of Walcheren, to deny the enemy this approach route to Vlissingen. Zuid-Beveland was connected to the coast of North Brabant by an isthmus; at its eastern and most narrow end the Bath Position had been prepared, occupied by an infantry battalion. At its western end was the longer Zanddijk Position, occupied by three battalions.

From 11 May the area was reinforced by two French infantry divisions: the 60e Division d'Infanterie, a B-class division, and the newly formed naval 68e Division d'Infanterie. Part of their equipment was brought by ship through Vlissingen harbour. Most troops of these divisions would remain south of the Western Scheldt in Zeeuws-Vlaanderen, where two of the eight Dutch battalions were also present, as were two border companies. Only two French regiments were sent to the northern bank. On 13 May the Dutch troops were placed under French operational command and 68e Division d'Infanterie was transferred to the 7th Army. The cooperation between the two allies left much to be desired and was plagued by poor communications, misunderstandings and differences regarding strategy. The Dutch considered the Bath and Zanddijk Positions to be very defensible because of the open polder landscape and extensive inundations. However, the French were not convinced of their value and positioned their troops at more conspicuous obstacles. On the evening of 13 May the 271e of 68e Division d'Infanterie occupied the Canal through Zuid-Beveland and the 224e of 60 Division d'Infanterie took a position at the Sloe straights separating the island of Walcheren from Zuid-Beveland, even though there was not sufficient time for adequate entrenchment. This prevented an effective concentration of Allied forces, allowing the Germans, despite a numerical inferiority, to defeat them piecemeal.

On 14 May the Germans occupied almost all of North Brabant. SS-Standarte Deutschland, quickly advancing to the Western Scheldt, reached the Bath Position. This cut off the retreat of 27e Groupe de Reconnaissance de Division d'Infanterie, which was subsequently destroyed defending Bergen-op-Zoom. The morale of the defenders, already shaken by stories from Dutch troops fleeing to the west, was severely undermined by the news that Winkelman had surrendered; many concluded that it was useless to keep resisting. A first preparatory artillery bombardment on the position in the evening of 14 May caused the commanding officers to desert their troops, who then also fled.

In the morning of 15 May SS-Standarte Deutschland approached the Zanddijk Position. A first attack around 08:00 on outposts of the northern sector was easily repulsed, as the Germans had to advance over a narrow dike through the inundations, despite air strikes by dive bombers. However, the bombardment caused the battalions in the main positions to flee, and the entire line had to be abandoned around 14:00 despite the southern part being supported by the French torpedo boat L'Incomprise.

On 16 May SS-Standarte Deutschland, some miles to the west of the Zanddijk Position, approached the Canal through Zuid-Beveland, where the French 271e Régiment d』Infanterie was present, only partly dug in and now reinforced by the three retreated Dutch battalions. An aerial bombardment that morning routed the defenders before the ground attack even started; the first German crossings around 11:00 led to a complete collapse. An attempt in the evening of the same day to force the eight hundred metres long dam over the Sloe, over which most of the French troops had fled to Walcheren, ended in failure. On 16 May the island of Tholen was taken against light opposition; on 17 May Schouwen-Duiveland fell.

While the commanders of the remaining Dutch troops on South-Beveland refused direct commands by their superior to threaten the German flank, on 17 May a night attack at 03:00 across the Sloe dam failed. The Germans now demanded the capitulation of the island; when this was refused they carpet bombed Arnemuiden, Vlissingen and Middelburg, the province's capital city, despite it being totally undefended. The heavy bombardment demoralised the largely French defenders and the Germans managed to establish a bridgehead around noon. The few Dutch troops present on Walcheren, about three companies, ceased their resistance. In the evening the encroaching Germans threatened to overrun the French forces that fled into Vlissingen, but a gallant delaying action by brigade general Marcel Deslaurens, in which he was killed, allowed most troops to be evacuated over the Western Scheldt.

After North-Beveland had surrendered on 18 May, Zeeuws-Vlaanderen was the last remaining unoccupied Dutch territory. On orders of the French, all Dutch troops were withdrawn on 19 May to Ostend in Belgium, as their presence would be demoralising and confusing their own forces. On 27 May all of Zeeuws-Vlaanderen had been occupied.