German invasion of the Netherlands

The German invasion of the Netherlands, also called the Battle of the Netherlands, was a big fight during World War II. It was part of a plan called Case Yellow by the Nazi German forces to take over several countries including the Low Countries like Belgium, Luxembourg, and the Netherlands, and then move on to France. This battle started on May 10, 1940. The main Dutch soldiers stopped fighting on May 14, 1940. But in the far southwest part of the country, called Zealand, Dutch troops kept fighting until May 17 when Germany took control of the whole Netherlands.

During this invasion, Germany used special soldiers called paratroop who dropped from airplanes to take important places. The German air force, known as the Luftwaffe, dropped these soldiers to capture airfields near cities like Rotterdam and The Hague. This helped Germany quickly take over the Netherlands.

One sad event happened when German planes bombed the city of Rotterdam on May 14, 1940. After this, the Germans told the Dutch that if they did not give up, they would bomb more cities. The Dutch leaders knew they could not stop the bombers, so they told their soldiers to stop fighting. Finally, in 1945, the last parts of the Netherlands were freed from German control.

Background

Prelude

On 1 September 1939, Nazi Germany began the invasion of Poland. On 3 September, France and the UK declared war on Germany, but no major land operations occurred in Western Europe during the winter of 1939–1940, a period known as the Phoney War. During this time, the British and French built up their forces for a long war. Nazi Germany and the Stalin regime had signed the Molotov–Ribbentrop Pact and completed their conquest of Poland in September 1939. On 9 October 1939, Adolf Hitler ordered plans to be made for an invasion of the Low Countries, to use them as a base against Great Britain and to prevent a similar attack by Western Allied forces, which could threaten the vital Ruhr Area. A joint Dutch-Belgian peace offer between the two sides was rejected on 7 November.

The Netherlands Armed Forces were not well-prepared to resist such an invasion. When the Hitler regime came to power, the Dutch had begun to re-arm, but more slowly than France or Belgium; only in 1936 did the defence budget start to be gradually increased. Successive Dutch governments tended to avoid openly identifying Nazi Germany as a military threat. Partly this was because they did not want to upset a vital trade partner, even to the point of repressing criticism of Nazi policies; partly it was because of strict budgetary limits with which the conservative Dutch governments tried to fight the Great Depression, which hit Dutch society hard. Hendrikus Colijn, Prime Minister of the Netherlands between 1933 and 1939, was convinced that Germany would not violate Dutch neutrality; senior officers did not try to mobilise public opinion to improve military defence.

International tensions grew since 1936: crises were caused by the German occupation of the Rhineland in March 1936; the Anschluss in March 1938, the Sudeten crisis in autumn 1938; the German occupation of Bohemia and Moravia in March 1939 and the Italian invasion of Albania in April 1939. These events forced the Dutch government to be more careful, but they limited their reaction as much as they could. The most important measure was a partial mobilisation of 100,000 men in April 1939.

After the German invasion of Poland in September 1939 and the outbreak of the Second World War, the Netherlands hoped to remain neutral, as it had done during World War I 25 years earlier. To ensure this neutrality, the Dutch army was mobilised from 24 August and entrenched. Large sums (almost 900 million guilders) were spent on defence. It proved very difficult to obtain new equipment in wartime, however, especially as the Dutch had ordered some of their new equipment from Germany, which deliberately delayed deliveries. Moreover, a considerable part of the funds were intended for the Dutch East Indies (now Indonesia), much of it related to a plan to build three battlecruisers.

The strategic position of the Low Countries, located between France and Germany, made the area a logical route for an offensive by either side. In a 20 January 1940 radio speech, Winston Churchill tried to convince them not to wait for an inevitable German attack, but to join the Anglo-French Entente. The governments of Belgium (Hubert Pierlot was PM since 22. February 1939) and the Netherlands (Second De Geer cabinet) refused, even though the German attack plans had fallen into Belgian hands after a German aircraft crash in January 1940, in what became known as the Mechelen Incident. The French supreme command considered violating the neutrality of the Low Countries if they had not joined the Anglo-French coalition before the planned large Entente offensive in the summer of 1941, but the French Cabinet, fearing a negative public reaction, vetoed the idea. Kept in consideration was a plan to invade if Germany attacked the Netherlands alone, necessitating an Entente advance through Belgium, or if the Netherlands assisted the enemy by tolerating a German advance into Belgium through the southern part of their territory, both possibilities discussed as part of the hypothèse Hollande. The Dutch government never officially formulated a policy on how to act in case of either contingency; the majority of ministers preferred to resist an attack, while a minority and Queen Wilhelmina refused to become a German ally whatever the circumstances. The Dutch tried on several occasions to act as an intermediary to reach a negotiated peace settlement between the Entente and Germany.

After the German invasion of Denmark and Norway, followed by a warning by the new Japanese naval attaché Captain Tadashi Maeda that a German attack on the Netherlands was certain, it became clear to the Dutch military that staying out of the conflict might prove impossible. They started to fully prepare for war, both mentally and physically. Dutch border troops were put on greater alert. Reports of the presumed actions of a fifth column in Scandinavia caused widespread fears that the Netherlands too had been infiltrated by German agents assisted by traitors. Countermeasures were taken against a possible assault on airfields and ports. A state of emergency was declared on 19 April. However, most civilians still hoped that their country might be spared, an attitude that has since been described as a state of denial. The Dutch hoped that the restrained policy of the Entente and Central Powers during the First World War might be repeated and tried to avoid the attention of the Great Powers and a war in which they feared a loss of human life comparable to that of the previous conflict. On 10 April, Britain and France repeated their request that the Dutch enter the war on their side, but were again refused.

Dutch forces

See also: List of Dutch regiments in World War II

Royal Netherlands Army

In the Netherlands, the country had many advantages for defence: a dense population, wealthy, young, disciplined and well-educated; a geography favouring the defender; and a strong technological and industrial base including an armaments industry. However, these had not been used: while the Wehrmacht at the time still had many shortcomings in equipment and training, the Dutch army, by comparison, was far less prepared for war. The myth of the general German equipment advantage over the opposing armies in the Battle of France was in fact a reality in the case of the Battle of the Netherlands. Germany had a modern army with tanks and dive bombers (such as the Junkers Ju 87 Stuka), while the Netherlands had an army whose armoured forces comprised only 39 armoured cars and five tankettes, and an air force in large part consisting of biplanes. The Dutch government's attitude towards war was reflected in the state of the country's armed forces, which had not significantly expanded their equipment since before the First World War, and were inadequately armed even by the standards of 1918. An economic recession lasting from 1920 until 1927 and the general détente in international relations caused a limitation of the defence budget. In that decade, only 1.5 million guilders per annum was spent on equipment. Both in 1931 and 1933, commissions appointed to economise even further failed, because they concluded that the acceptable minimum had been reached and advised that a spending increase was urgently needed. Only in February 1936 was a bill passed creating a special 53.4 million guilder defence fund.

The lack of a trained manpower base, a large professional organisation, or sufficient matériel reserves precluded a swift expansion of Dutch forces. There was just enough artillery to equip the larger units: eight infantry divisions (combined in four Army Corps), one Light (i.e. motorised) Division and two independent brigades (Brigade A and Brigade B), each with the strength of half a division or five battalions. All other infantry combat unit troops were raised as light infantry battalions that were dispersed all over the territory to delay enemy movement. About two thousand pillboxes had been constructed, but in lines without any depth. Modern large fortresses like the Belgian stronghold of Eben Emael were nonexistent; the only modern fortification complex was that at Kornwerderzand, guarding the Afsluitdijk. Total Dutch forces equalled 48 regiments of infantry as well as 22 infantry battalions for strategic border defence. In comparison, Belgium, despite a smaller and more aged male population, fielded 22 full divisions and the equivalent of 30 divisions when smaller units were included.

After September 1939, desperate efforts were made to improve the situation, but with very little result. Germany, for obvious reasons, delayed its deliveries; France was hesitant to equip an army that would not unequivocally take its side. The one abundant source of readily available weaponry, the Soviet Union, was inaccessible because the Dutch, contrary to most other nations, did not recognise the communist regime. An attempt in 1940 to procure Soviet armour captured by Finland failed.

On 10 May, the most conspicuous deficiency of the Dutch Army lay in its shortage of armour. Whereas the other major participants all had a considerable armoured force, the Netherlands had not been able to obtain the minimum of 146 modern tanks (110 light, 36 medium) they had already considered necessary in 1937. A single Renault FT tank, for which just one driver had been trained and which had the sole task of testing antitank obstacles, had remained the only example of its kind and was no longer in service by 1940. There were two squadrons of armoured cars, each with a dozen Landsverk M36 or M38 vehicles. Another dozen DAF M39 cars were in the process of being taken into service, some still having to be fitted with their main armament. A single platoon of five Carden-Loyd Mark VI tankettes used by the Artillery completed the list of Dutch armour.

The Dutch Artillery had available a total of 676 howitzers and field guns: 310 Krupp 75 mm field guns, partly produced in licence; 52 105 mm Bofors howitzers, the only really modern pieces; 144 obsolete Krupp 125 mm guns; 40 150 mm sFH13's; 72 Krupp 150 mm L/24 howitzers and 28 Vickers 152 mm L/15 howitzers. As antitank-guns 386 Böhler 47 mm L/39s were available, which were effective weapons but too few in number, being only at a third of the planned strength; another three hundred antiquated 6 Veld (57 mm) and 8 cm staal (84 mm) field guns performed the same role for the covering forces. Only eight of the 120 modern 105 mm pieces ordered from Germany had been delivered at the time of the invasion. Most artillery was horse-drawn. Volunteers were equipped with Oerlikon 20 mm cannons for air defence.

The Dutch Infantry used about 2,200 7.92 mm Schwarzlose M.08 machine guns, partly licence produced, and eight hundred Vickers machine guns. Many of these were fitted in the pillboxes; each battalion had a heavy machine gun company of twelve. The Dutch infantry squads were equipped with an organic light machine gun, the M.20 Lewis machine gun, of which about eight thousand were available. Most Dutch infantry were equipped with the Geweer M.95 rifle, adopted in 1895. There were but six 80 mm mortars for each regiment. This lack of firepower seriously impaired the fighting performance of the Dutch infantry.

Despite the Netherlands being the seat of Philips, one of Europe's largest producers of radio equipment, the Dutch army mostly used telephone connections; only the Artillery had been equipped with the modest number of 225 radio sets.

Dutch air forces

The Dutch air force, which was not an independent arm of the Dutch armed forces, but part of the Army, on 10 May operated a fleet of 155 aircraft: 28 Fokker G.1 twin-engine destroyers; 31 Fokker D.XXI and seven Fokker D.XVII fighters; ten twin-engined Fokker T.V, fifteen Fokker C.X and 35 Fokker C.V light bombers, twelve Douglas DB-8 dive bombers (used as fighters) and seventeen Koolhoven FK-51 reconnaissance aircraft—thus 74 of the 155 aircraft were biplanes. Of these aircraft 125 were operational. Of the remainder the air force school used three Fokker D.XXI, six Fokker D.XVII, a single Fokker G.I, a single Fokker T.V and seven Fokker C.V, along with several training aeroplanes. Another forty operational aircraft served with the Marineluchtvaartdienst (naval air service) along with about an equal number of reserve and training craft. The production potential of the Dutch military aircraft industry, consisting of Fokker and Koolhoven, was not fully exploited due to budget limitations.

Training and readiness

Not only was the Royal Netherlands Army poorly equipped, it was also poorly trained. A particular problem was the absence of 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. Adding to this shortcoming, 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 for by the presence of 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 for improving training 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 was incapable of staging an offensive, even at division level, while executing manoeuvre warfare was far beyond its capacities.

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

In the 17th century, the Dutch Republic had devised a defensive system called the Hollandic Water Line, which during the Franco-Dutch War protected 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 Hollandic 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 Hollandic 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: the Meuse (Maas) and two branches of the Rhine. 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 Valley, 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 invade 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 Utrechtse Heuvelrug, 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 Maas and the Belgian border along the Peel Marshes and the Raam River, 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

In front of this Main Defence Line was the IJssel-Maaslinie, a covering line along the rivers IJssel and Meuse (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 co-ordinate 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 co-ordination with Entente troops. This made it difficult for the Dutch to have these plans changed again to suit their wishes. The Dutch desired the Belgians to connect their defences to the Peel-Raam Position, that Reijnders refused to abandon without a fight. 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. 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 planned 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.

After the German attack on Denmark and Norway in April 1940, when the Germans used large numbers of airborne troops, the Dutch command became worried about the possibility they too could become the victim of such a strategic assault. To repulse an attack, five infantry battalions were positioned at the main ports and airbases, such as The Hague airfield of Ypenburg and the Rotterdam airfield of Waalhaven. These were reinforced by additional AA-guns, two tankettes and twelve of the 24 operational armoured cars. These specially directed measures were accompanied by more general ones: the Dutch had posted no less than 32 hospital ships throughout the country and fifteen trains to help make troop movements easier.

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 in this region. For the Germans this would have the advantage of bypassing the Antwerp-Namur line. The Zealand Isles were considered to be strategically critical, as they are just opposite 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 and preserve an allied left flank beyond the Rhine. 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 Islands. Hermann Göring insisted on a full conquest, for he needed the Dutch airfields against Britain; also, he was afraid that 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 on central Belgium was only a feint—and the attack on Fortress Holland only a sideshow of this feint. Although both the 6th and 18th Army were deployed on 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 Division), assisted by three reserve divisions (208th, 225th, and 526th Infantry Division) 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 little fighting experience apart from those who 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 serious combat training. The German divisions, with a nominal strength of 17,807 men, were fifty percent larger than their Dutch counterparts and possessed twice their effective firepower, but even so 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, the aptly named 1st Kavalleriedivision. These mounted troops, 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 11⁄3 division to the equation.

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 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. This was the only German armoured division having just two tank battalions, one understrength, in its single tank regiment; the total number of tanks in the unit was 141. The intention was that it should exploit a breach in the Dutch lines created by the 254th and 256th Infantry Division, 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 Division, 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 over the Moerdijk bridges 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. Armeekorp 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. German propaganda therefore justified the invasion as a reaction to a supposed Entente attempt to occupy the Low Countries, similar to the justification used by the German Empire to invade Belgium in World War I. Some German officers were averse to the Nazi regime and were also uneasy about the invasion.

One of them, Colonel Hans Oster, an Abwehr (German military 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, several postponements while the Germans waited for favourable weather conditions led to a series of false alarms, which left the Dutch government and others somewhat sceptical of the information. 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 Fortress Holland from North Brabant and that there was a plan to capture the Queen, 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 on the evening of 9 May Oster again phoned his friend saying just "Tomorrow, at dawn", 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 Hitler.

Return only the adapted Markdown section. No explanation, no preamble## Background

Prelude

On 1 September 1939, Nazi Germany began the invasion of Poland. On 3 September, France and the UK declared war on Germany, but no major land operations occurred in Western Europe during the winter of 1939–1940, a period known as the Phoney War. During this time, the British and French built up their forces for a long war. Nazi Germany and the Stalin regime had signed the Molotov–Ribbentrop Pact and completed their conquest of Poland in September 1939. On 9 October 1939, Adolf Hitler ordered plans to be made for an invasion of the Low Countries, to use them as a base against Great Britain and to prevent a similar attack by Western Allied forces, which could threaten the vital Ruhr Area. A joint Dutch-Belgian peace offer between the two sides was rejected on 7 November.

The Netherlands Armed Forces were not well-prepared to resist such an invasion. When the Hitler regime came to power, the Dutch had begun to re-arm, but more slowly than France or Belgium; only in 1936 did the defence budget start to be gradually increased. Successive Dutch governments tended to avoid openly identifying Nazi Germany as a military threat. Partly this was because they did not want to upset a vital trade partner, even to the point of repressing criticism of Nazi policies; partly it was because of strict budgetary limits with which the conservative Dutch governments tried to fight the Great Depression, which hit Dutch society hard. Hendrikus Colijn, Prime Minister of the Netherlands between 1933 and 1939, was convinced that Germany would not violate Dutch neutrality; senior officers did not try to mobilise public opinion to improve military defence.

International tensions grew since 1936: crises were caused by the German occupation of the Rhineland in March 1936; the Anschluss in March 1938, the Sudeten crisis in autumn 1938; the German occupation of Bohemia and Moravia in March 1939 and the Italian invasion of Albania in April 1939. These events forced the Dutch government to be more careful, but they limited their reaction as much as they could. The most important measure was a partial mobilisation of 100,000 men in April 1939.

After the German invasion of Poland in September 1939 and the outbreak of the Second World War, the Netherlands hoped to remain neutral, as it had done during World War I 25 years earlier. To ensure this neutrality, the Dutch army was mobilised from 24 August and entrenched. Large sums (almost 900 million guilders) were spent on defence. It proved very difficult to obtain new equipment in wartime, however, especially as the Dutch had ordered some of their new equipment from Germany, which deliberately delayed deliveries. Moreover, a considerable part of the funds were intended for the Dutch East Indies (now Indonesia), much of it related to a plan to build three battlecruisers.

The strategic position of the Low Countries, located between France and Germany, made the area a logical route for an offensive by either side. In a 20 January 1940 radio speech, Winston Churchill tried to convince them not to wait for an inevitable German attack, but to join the Anglo-French Entente. The governments of Belgium (Hubert Pierlot was PM since 22. February 1939) and the Netherlands (Second De Geer cabinet) refused, even though the German attack plans had fallen into Belgian hands after a German aircraft crash in January 1940, in what became known as the Mechelen Incident. The French supreme command considered violating the neutrality of the Low Countries if they had not joined the Anglo-French coalition before the planned large Entente offensive in the summer of 1941, but the French Cabinet, fearing a negative public reaction, vetoed the idea. Kept in consideration was a plan to invade if Germany attacked the Netherlands alone, necessitating an Entente advance through Belgium, or if the Netherlands assisted the enemy by tolerating a German advance into Belgium through the southern part of their territory, both possibilities discussed as part of the hypothèse Hollande. The Dutch government never officially formulated a policy on how to act in case of either contingency; the majority of ministers preferred to resist an attack, while a minority and Queen Wilhelmina refused to become a German ally whatever the circumstances. The Dutch tried on several occasions to act as an intermediary to reach a negotiated peace settlement between the Entente and Germany.

After the German invasion of Denmark and Norway, followed by a warning by the new Japanese naval attaché Captain Tadashi Maeda that a German attack on the Netherlands was certain, it became clear to the Dutch military that staying out of the conflict might prove impossible. They started to fully prepare for war, both mentally and physically. Dutch border troops were put on greater alert. Reports of the presumed actions of a fifth column in Scandinavia caused widespread fears that the Netherlands too had been infiltrated by German agents assisted by traitors. Countermeasures were taken against a possible assault on airfields and ports. A state of emergency was declared on 19 April. However, most civilians still hoped that their country might be spared, an attitude that has since been described as a state of denial. The Dutch hoped that the restrained policy of the Entente and Central Powers during the First World War might be repeated and tried to avoid the attention of the Great Powers and a war in which they feared a loss of human life comparable to that of the previous conflict. On 10 April, Britain and France repeated their request that the Dutch enter the war on their side, but were again refused.

Dutch forces

See also: List of Dutch regiments in World War II

Royal Netherlands Army

In the Netherlands, the country had many advantages for defence: a dense population, wealthy, young, disciplined and well-educated; a geography favouring the defender; and a strong technological and industrial base including an armaments industry. However, these had not been used: while the Wehrmacht at the time still had many shortcomings in equipment and training, the Dutch army, by comparison, was far less prepared for war. The myth of the general German equipment advantage over the opposing armies in the Battle of France was in fact a reality in the case of the Battle of the Netherlands. Germany had a modern army with tanks and dive bombers (such as the Junkers Ju 87 Stuka), while the Netherlands had an army whose armoured forces comprised only 39 armoured cars and five tankettes, and an air force in large part consisting of biplanes. The Dutch government's attitude towards war was reflected in the state of the country's armed forces, which had not significantly expanded their equipment since before the First World War, and were inadequately armed even by the standards of 1918. An economic recession lasting from 1920 until 1927 and the general détente in international relations caused a limitation of the defence budget. In that decade, only 1.5 million guilders per annum was spent on equipment. Both in 1931 and 1933, commissions appointed to economise even further failed, because they concluded that the acceptable minimum had been reached and advised that a spending increase was urgently needed. Only in February 1936 was a bill passed creating a special 53.4 million guilder defence fund.

The lack of a trained manpower base, a large professional organisation, or sufficient matériel reserves precluded a swift expansion of Dutch forces. There was just enough artillery to equip the larger units: eight infantry divisions (combined in four Army Corps), one Light (i.e. motorised) Division and two independent brigades (Brigade A and Brigade B), each with the strength of half a division or five battalions. All other infantry combat unit troops were raised as light infantry battalions that were dispersed all over the territory to delay enemy movement. About two thousand pillboxes had been constructed, but in lines without any depth. Modern large fortresses like the Belgian stronghold of Eben Emael were nonexistent; the only modern fortification complex was that at Kornwerderzand, guarding the Afsluitdijk. Total Dutch forces equalled 48 regiments of infantry as well as 22 infantry battalions for strategic border defence. In comparison, Belgium, despite a smaller and more aged male population, fielded 22 full divisions and the equivalent of 30 divisions when smaller units were included.

After September 1939, desperate efforts were made to improve the situation, but with very little result. Germany, for obvious reasons, delayed its deliveries; France was hesitant to equip an army that would not unequivocally take its side. The one abundant source of readily available weaponry, the Soviet Union, was inaccessible because the Dutch, contrary to most other nations, did not recognise the communist regime. An attempt in 1940 to procure Soviet armour captured by Finland failed.

On 10 May, the most conspicuous deficiency of the Dutch Army lay in its shortage of armour. Whereas the other major participants all had a considerable armoured force, the Netherlands had not been able to obtain the minimum of 146 modern tanks (110 light, 36 medium) they had already considered necessary in 1937. A single Renault FT tank, for which just one driver had been trained and which had the sole task of testing antitank obstacles, had remained the only example of its kind and was no longer in service by 1940. There were two squadrons of armoured cars, each with a dozen Landsverk M36 or M38 vehicles. Another dozen DAF M39 cars were in the process of being taken into service, some still having to be fitted with their main armament. A single platoon of five Carden-Loyd Mark VI tankettes used by the Artillery completed the list of Dutch armour.

The Dutch Artillery had available a total of 676 howitzers and field guns: 310 Krupp 75 mm field guns, partly produced in licence; 52 105 mm Bofors howitzers, the only really modern pieces; 144 obsolete Krupp 125 mm guns; 40 150 mm sFH13's; 72 Krupp 150 mm L/24 howitzers and 28 Vickers 152 mm L/15 howitzers. As antitank-guns 386 Böhler 47 mm L/39s were available, which were effective weapons but too few in number, being only at a third of the planned strength; another three hundred antiquated 6 Veld (57 mm) and 8 cm staal (84 mm) field guns performed the same role for the covering forces. Only eight of the 120 modern 105 mm pieces ordered from Germany had been delivered at the time of the invasion. Most artillery was horse-drawn. Volunteers were equipped with Oerlikon 20 mm cannons for air defence.

The Dutch Infantry used about 2,200 7.92 mm Schwarzlose M.08 machine guns, partly licence produced, and eight hundred Vickers machine guns. Many of these were fitted in the pillboxes; each battalion had a heavy machine gun company of twelve. The Dutch infantry squads were equipped with an organic light machine gun, the M.20 Lewis machine gun, of which about eight thousand were available. Most Dutch infantry were equipped with the Geweer M.95 rifle, adopted in 1895. There were but six 80 mm mortars for each regiment. This lack of firepower seriously impaired the fighting performance of the Dutch infantry.

Despite the Netherlands being the seat of Philips, one of Europe's largest producers of radio equipment, the Dutch army mostly used telephone connections; only the Artillery had been equipped with the modest number of 225 radio sets.

Dutch air forces

The Dutch air force, which was not an independent arm of the Dutch armed forces, but part of the Army, on 10 May operated a fleet of 155 aircraft: 28 Fokker G.1 twin-engine destroyers; 31 Fokker D.XXI and seven Fokker D.XVII fighters; ten twin-engined Fokker T.V, fifteen Fokker C.X and 35 Fokker C.V light bombers, twelve Douglas DB-8 dive bombers (used as fighters) and seventeen Koolhoven FK-51 reconnaissance aircraft—thus 74 of the 155 aircraft were biplanes. Of these aircraft 125 were operational. Of the remainder the air force school used three Fokker D.XXI, six Fokker D.XVII, a single Fokker G.I, a single Fokker T.V and seven Fokker C.V, along with several training aeroplanes. Another forty operational aircraft served with the Marineluchtvaartdienst (naval air service) along with about an equal number of reserve and training craft. The production potential of the Dutch military aircraft industry, consisting of Fokker and Koolhoven, was not fully exploited due to budget limitations.

Training and readiness

Not only was the Royal Netherlands Army poorly equipped, it was also poorly trained. A particular problem was the absence of 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. Adding to this shortcoming, 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 for by the presence of 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 for improving training 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 was incapable of staging an offensive, even at division level, while executing manoeuvre warfare was far beyond its capacities.

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

In the 17th century, the Dutch Republic had devised a defensive system called the Hollandic Water Line, which during the Franco-Dutch War protected 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 Hollandic 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 Hollandic 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: the Meuse (Maas) and two branches of the Rhine. 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 Valley, 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 invade 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 Utrechtse Heuvelrug, 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 Maas and the Belgian border along the Peel Marshes and the Raam River, 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

In front of this Main Defence Line was the IJssel-Maaslinie, a covering line along the rivers IJssel and Meuse (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 co-ordinate 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 co-ordination with Entente troops. This made it difficult for the Dutch to have these plans changed again to suit their wishes. The Dutch desired the Belgians to connect their defences to the Peel-Raam Position, that Reijnders refused to abandon without a fight. 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. 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 planned 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.

After the German attack on Denmark and Norway in April 1940, when the Germans used large numbers of airborne troops, the Dutch command became worried about the possibility they too could become the victim of such a strategic assault. To repulse an attack, five infantry battalions were positioned at the main ports and airbases, such as The Hague airfield of Ypenburg and the Rotterdam airfield of Waalhaven. These were reinforced by additional AA-guns, two tankettes and twelve of the 24 operational armoured cars. These specially directed measures were accompanied by more general ones: the Dutch had posted no less than 32 hospital ships throughout the country and fifteen trains to help make troop movements easier.

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 in this region. For the Germans this would have the advantage of bypassing the Antwerp-Namur line. The Zealand Isles were considered to be strategically critical, as they are just opposite 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 and preserve an allied left flank beyond the Rhine. 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 Islands. Hermann Göring insisted on a full conquest, for he needed the Dutch airfields against Britain; also, he was afraid that 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 on central Belgium was only a feint—and the attack on Fortress Holland only a sideshow of this feint. Although both the 6th and 18th Army were deployed on 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 Division), assisted by three reserve divisions (208th, 225th, and 526th Infantry Division) 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 little fighting experience apart from those who 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 serious combat training. The German divisions, with a nominal strength of 17,807 men, were fifty percent larger than their Dutch counterparts and possessed twice their effective firepower, but even so 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, the aptly named 1st Kavalleriedivision. These mounted troops, 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 11⁄3 division to the equation.

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 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. This was the only German armoured division having just two tank battalions, one understrength, in its single tank regiment; the total number of tanks in the unit was 141. The intention was that it should exploit a breach in the Dutch lines created by the 254th and 256th Infantry Division, 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 Division, 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 over the Moerdijk bridges 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. Armeekorp 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. German propaganda therefore justified the invasion as a reaction to a supposed Entente attempt to occupy the Low Countries, similar to the justification used by the German Empire to invade Belgium in World War I. Some German officers were averse to the Nazi regime and were also uneasy about the invasion.

One of them, Colonel Hans Oster, an Abwehr (German military 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, several postponements while the Germans waited for favourable weather conditions led to a series of false alarms, which left the Dutch government and others somewhat sceptical of the information. 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 Fortress Holland from North Brabant and that there was a plan to capture the Queen, 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 on the evening of 9 May Oster again phoned his friend saying just "Tomorrow, at dawn", 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 Hitler.

Battle

On the morning of 10 May 1940, Germany attacked the Netherlands as part of a plan to invade several countries. The attack was a surprise and included airplanes and soldiers landing near airfields. Dutch forces tried to defend against the attack, but many of their planes were destroyed.

The Germans wanted to quickly capture important bridges and areas. In some places, like Rotterdam, they were successful. In other places, like The Hague, they faced strong resistance. The Dutch forces were spread out, and the fast German advance caused confusion and retreat in many areas.

Over the next few days, fighting continued with the Dutch trying to hold their positions and the Germans moving forward. By 14 May, the situation became very difficult for the Dutch, especially after a large bombing of Rotterdam, which led to the city's surrender. The Dutch forces were eventually overwhelmed, and the country was occupied by German troops.

The surrender of the Dutch Army

General Winkelman decided to stop fighting even though some cities had been taken. He was worried the Germans might destroy more cities. He thought stopping the fighting would help prevent more suffering. He told all Dutch soldiers to destroy their weapons and surrender to German troops. He announced this on the radio so everyone would know.

Winkelman was in charge of both the army and the government. Some navy leaders had already left, and some ships tried to escape to England. It took time to convince all soldiers to surrender. The next day, Winkelman met with German leaders. They signed a document agreeing the Dutch army would stop fighting, but some forces would keep resisting.

The fighting in Zealand

The area of Zealand kept fighting even after the rest of the Netherlands had surrendered. Dutch troops there worked together with French soldiers. They tried to defend important places, but had trouble working together.

German forces pushed into Zealand and attacked the Dutch and French positions. By the end of May, the Germans had taken control of all of Zealand.

Aftermath

Main article: Netherlands in World War II

After the Netherlands lost the battle, Queen Wilhelmina went to Britain to lead a government-in-exile. Germany took control of the country on May 17, 1940. It took five years to free the Netherlands from German control. During this time, many people had hard times because of the war. Some groups were treated unfairly, and there were also problems with food and medical care.