Introduction

The German bombing of Rotterdam, also known as the Rotterdam Blitz, was the aerial bombardment of Rotterdam by the Luftwaffe on 14 May 1940, during the German invasion of the Netherlands in World War II. The objective was to support the German troops fighting in the city, break Dutch resistance and force the Dutch army to surrender. Almost the entire historic city centre was destroyed, nearly 900 people were killed and 85,000 more were left homeless.

The psychological and physical success of the raid, from the German perspective, led the Oberkommando der Luftwaffe (OKL) to threaten to destroy the city of Utrecht if the Dutch command did not surrender. The Dutch surrendered in the late afternoon of 14 May, signing the capitulation early the next morning.

Background

During the Second World War, the Netherlands’ strategic location between Great Britain and Germany made it ideal for the basing of German air and naval forces to be used in attacks on the British Isles. The Netherlands had firmly opted for neutrality throughout the First World War and had planned to do the same for the Second World War. It had refused armaments from France, making the case that they wanted no association with either side. While armament production was slightly increased after the invasion of Denmark in April 1940, the Netherlands possessed only 35 modern wheeled armoured fighting vehicles, five tracked armoured fighting vehicles, 135 aircraft, and 280,000 soldiers, while Germany committed 159 tanks, 1,200 modern aircraft, and around 150,000 soldiers to the Dutch theatre alone.

With a significant military advantage, the German leadership intended to expedite the conquest of the country by first taking control of key military and strategic targets, such as airfields, bridges, and roads, and then using these to gain control of the remainder of the country. The first German plans to invade the Netherlands were articulated on 09 October 1939, when Hitler ordered that “Preparations should be made for offensive action on the northern flank of the Western Front crossing the area of Luxembourg, Belgium, and the Netherlands.” This attack was to be carried out as quickly and as forcefully as possible. Hitler ordered German intelligence officers to capture Dutch army uniforms and use them to gain detailed information on Dutch defensive preparations.

The Wehrmacht launched its invasion of the Netherlands in the early hours of 10 May 1940. The attack started with the Luftwaffe crossing through Dutch airspace, giving the impression that Britain was the ultimate target. Instead, the aircraft turned around over the North Sea and returned to attack from the west, dropping paratroopers at Valkenburg and Ockenburg airfields, near the Dutch seat of government and the Royal Palace in The Hague, starting the Battle for the Hague. While Germany had planned to take control swiftly using this strategy, the assault on The Hague failed. However, bridges were taken at the Moerdijk, Dort and Rotterdam, allowing armoured forces to enter the core region of the Fortress Holland on 13 May.

The Battle for Rotterdam

The situation in Rotterdam on the morning of 13 May 1940 was a stalemate as it had been over the previous three days. Dutch garrison forces under Colonel P.W. Scharroo held the north bank of the Nieuwe Maas river, which runs through the city and prevented the Germans from crossing; German forces included airlanding and airborne forces of General Student and newly arrived ground forces under General Schmidt, based on the 9th Panzer Division and the Leibstandarte Adolf Hitler, a motorised SS regiment.

A Dutch counterattack led by a Dutch marine company had failed to recapture the Willemsbrug traffic bridge, the key crossing. Several efforts by the Dutch Army Aviation Brigade to destroy the bridge also failed.

On the Morning of 14 May, Hitler issued his “Weisung” Nr. 11. Concerning the Dutch theatre of operations he says the following:

The resistance capability of the Dutch army has proved to be stronger than expected. Political as well as military reasons demand that this resistance is broken as soon as possible. It is the task of the army to capture the Fortress Holland by committing enough forces from the south, combined with an attack on the east front. In addition to that the air force must, while weakening the forces that up till now have supported the 6th Army, facilitate the rapid fall of the Fortress Holland.

General Schmidt had planned a combined assault the next day, 14 May, using tanks of the 9th Panzer supported by flame throwers, SS troops and combat engineers. The airlanding troops were to make an amphibious crossing of the river upstream and then a flank attack through the Kralingen district. The attack was to be preceded by artillery bombardment, while Gen. Schmidt had requested the support of the Luftwaffe in the form of a Gruppe (about 25 aircraft) of Junkers Ju 87 dive-bombers, specifically for a precision raid.

Schmidt’s request for air support reached Berlin, staff of Luftflotte 2. Instead of precision bombers, Schmidt got carpet bombing by Heinkel He 111 bombers besides a Gruppe of Stukas focussing on some strategic targets. The carpet bombing had been ordered by Hermann Göring, to force a Dutch national capitulation.

The Bombing

Schmidt used the threat of destroying Rotterdam to attempt to force Colonel Scharroo to surrender the city. Rotterdam, the largest industrial centre in the Netherlands and of major strategic importance to the Germans, was to be bombed. Scharroo refused and stretched out negotiations. The start of the air raid had been set for 13:20 [Dutch time, MET – 1 hr 40].

Schmidt relented and issued a second ultimatum of 16:20. However, it was already too late and just as the Dutch negotiator was crossing the Willemsbrug to relay this information, the drone of bombers was heard: a total of 90 bombers from Kampfgeschwader 54 were sent over the city.

Schmidt radioed to postpone the planned attack. When the message reached KG 54’s command post, the Kommodore, Oberst Walter Lackner, was already approaching Rotterdam and his aircraft had reeled in their long-range aerials. Haze and smoke obscured the target and to ensure that Dutch defences were struck, Lackner brought his formation down to 2,300 ft (700 m). German forces on the Noordereiland fired flares to prevent friendly fire – after three aircraft of the southern formation had already unloaded, the remaining 24 craft in the southern bomber formation under Oberstleutnant Otto Höhne aborted their attack. The larger formation came from the north-east. Unable to see the red flares launched from the southern area of the city, they proceeded with their attack. Fifty-four He 111s dropped low to release 97 tonnes (213,848 lb) of bombs, mainly in the centre of the city.

Why the formation did not receive the order to abort sooner remains a subject of some controversy. Oberst Lackner of the largest formation claimed that his crews had been unable to spot the red flares due to bad visibility caused by humidity and the dense smoke rising from burning structures, and that they had consequently needed to drop to 2,000 feet. But the red flares that Lackner failed to see could have also been used by the Germans to show their location in the city and avoid friendly fire. An official German form designated red as the colour to be used for that purpose.

In total, 1,150 50-kilogram (110 lb) and 158 250-kilogram (550 lb) of bombs were dropped on the city, mainly in the residential areas of Kralingen and the medieval city centre. Most of them struck buildings which immediately went up in flames. The fires across the city centre spread uncontrollably and in the subsequent days they were aggravated as the wind grew stronger, merging to become a firestorm. Although the exact number of casualties is not known, it is estimated that approximately 1,000 people were killed and 85,000 were made homeless. Around 2.6 square kilometres (1.0 square miles) of the city was levelled. 24,978 homes, 24 churches, 2,320 stores, 775 warehouses and 62 schools were destroyed. Schmidt sent a conciliatory message to the Dutch commander General Winkelman, who surrendered shortly afterwards at Rijsoord, a village southeast of Rotterdam. The school where the Dutch capitulated was later turned into a small museum.

Aftermath and Legacy

The Dutch military had no effective means of stopping the bombers (the Dutch Air Force had practically ceased to exist and its anti-aircraft guns had been moved to The Hague), so when another similar ultimatum was given in which the Germans threatened to bomb the city of Utrecht, the Dutch supreme command in the late afternoon decided to capitulate rather than risk the destruction of another city. Dutch and British sources informed the public through Allied and international news media that the raid on Rotterdam had been on an open city in which 30,000 civilians were killed (the real number was around 900) “and character[ised] the German demolition of the old city as an act of unmitigated barbarism”. The number of casualties was relatively small, because thousands of civilians had fled to safer parts of Rotterdam, or to other cities, during the previous four days of bombing and warfare. German weekly Die Mühle (The Windmill) stated that the Dutch government was to blame for turning Rotterdam into a fortress, despite multiple summons to evacuate. It also claimed that the old city was ignited by Dutch bombs and incendiary devices.

The United Kingdom had had a policy of bombing only military targets and infrastructure such as ports and railways which were of military importance. While it was acknowledged that bombing of Germany would cause civilian casualties, the British government renounced the deliberate bombing of civilian property outside combat zones (which after the fall of Poland, meant German areas east of the Rhine) as a military tactic. This policy was abandoned on 15 May 1940, one day after the Rotterdam Blitz, when the RAF was directed to attack targets in the Ruhr, including oil plants and other civilian industrial targets which aided the German war effort, such as blast furnaces that at night were self-illuminating. The first RAF raid on the interior of Germany took place on the night of 15/16 May 1940.

When the invasion of Holland took place I was recalled from leave and went on my first operation on 15 May 1940 against mainland Germany. Our target was Dortmund and on the way back we were routed via Rotterdam. The German Air Force had bombed Rotterdam the day before and it was still in flames. I realised then only too well that the phoney war was over and that this was for real. By that time the fire services had extinguished a number of fires, but they were still dotted around the whole city. This was the first time I’d ever seen devastation by fires on this scale. We went right over the southern outskirts of Rotterdam at about 6,000 or 7,000 feet, and you could actually smell the smoke from the fires burning on the ground. I was shocked seeing a city in flames like that. Devastation on a scale I had never experienced. Air Commodore Wilf Burnett.