In Rotterdam, the Dutch failed to kill the German airborne troops from their bridge on the northern bank of the Maas. The two remaining Dutch bombers failed to destroy the "Willemsbrug". None of the attempts to kill the groups of 1600 paratroopers and airlanded forces was successful.
In North Brabant, the situation got worse. The French commanders of the 7th Army had expected that Dutch fighting would give them four days to build up a defensive line near Breda. However, the best three divisions had been moved to the north and the remaining forces were retreating.
The withdrawal of the Peel Division from the Peel-Raam Position to the Zuid-Willemsvaart, a canal to the west, meant leaving behind their trenches and artillery for a totally unprepared line. The eastern bank of the canal was higher than the western bank, providing excellent cover for the attackers.
One part of the canal, near Heeswijk, was left undefended; as this area contained a bridge which was not destroyed, the Germans were able to cross the canal around 13:00.
A second crossing at Erp, led to a 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 fallen apart. The French refused to advance further to the northeast than Tilburg, apart from some armoured cars that went as far as Berlicum.
Winkelman asked the British government to sent an Army Corps to add to allied positions in the area and bomb Waalhaven airfield.
Motorised elements of "SS Standarte "Der Fuehrer"" 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 was protected by a line of outposts and two groups of infantry.
At about half past three in the morning of the 11th, German artillery started bombing the outposts. At dawn, two battalions of "Der Fuehrer" attacked. As the German bombing had cut the telephone lines, no artillery could be requested by the Dutch defenders.
The vegetation offered good cover for the attackers. At noon, the Germans broke a hole at the extreme north. By evening, all outposts were held by the Germans.
The commander of 2nd Army Corps, Major-General Jacob Harberts, did not realise that motorised SS troops had been involved in the attack. He thought that the outposts had surrendered to a small German force. He ordered a night attack by the single reserve battalion of 4th Division.
This attack was abandoned. However, heavy Dutch artillery fire caused the Germans to abandon their plans for a night attack.
Meanwhile, in the North, "1. Kavalleriedivision" advanced through the province of Friesland, reaching Sneek in the evening. Most Dutch troops had been evacuated from the north.
On the morning of 12 May General Winkelman still had hope. He thought a defence line could be set up in North Brabant with the help of the French. He also expected that the Dutch could kill the German airborne forces. He was not aware of any danger to the Grebbe Line.
"9. Panzerdivision" crossed the Meuse in the early morning of 11 May. It could not advance quickly over roads filled with infantry. The armoured division was told to join with the airborne troops as soon as the Peel-Raam Position had been captured by the infantry forces.
Because the German 6th Army was threatening its right side and there was no time to prepare a defence line, Gamelin ordered the 7th Army to withdraw its left side. "2e Brigade Légère Mécanique" retreated to the south.
The 9th Panzer Division took Colonel Schmidt prisoner. The Dutch troops in the province lost all command. Shortly after noon the German armoured cars got thirty kilometres more to the west, cutting off the Fortress Holland from the Allied main force. At 16:45 they had reached the bridges.
At 13:35 Gamelin ordered a withdrawal to Antwerp of all French troops in North-Brabant.
The Light Division tried to recapture the Island of Dordrecht by advancing with four battalions with little artillery support. On its left side, where there was almost no enemies, the advance went well. The battalion on the right side ran into an attacking German battalion. In the street fighting the German troops blocked the battalion. The other Dutch units then halted their advance around noon. No attack was made that day.
In Rotterdam and around The Hague little was done against the paratroopers. Most Dutch commanders did not attack.
In the east the Germans attacked the Dutch defenders on the "Grebbeberg". After artillery bombing in the morning, at around noon a battalion of "Der Fuehrer" attacked the main line, occupied by a Dutch company.
The Germans got through the thin line. A second German battalion then attacked to the north. Dutch artillery, though equal in strength to the Germans, did not fire on the enemy infantry.
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 the area under their control. Spotting a weak point, one of the SS battalion commanders, Obersturmbannführer Hilmar Wäckerle, attacked. The defenders mostly abandoned their positions. The SS company became surrounded.
The earlier German advance later caused the main line to be abandoned for over two miles to the north because the troops there feared an attack from behind.
The Dutch knew that the forces on the Grebbe Line would not be strong enough to stop all attacks by themselves. They were intended to delay an attack long enough for new troops to be sent. In the late evening it was decided to attack from the north the next day.
In the North, the Wons position had a long perimeter of about nine kilometres, which gave space for retreating troops. On 12 May units with a combined strength of only two battalions were still present, so the line was weakly held. The first German unit to arrive broke through. This forced the defenders to withdraw to the Enclosure Dike.
General Winkelman ordered the artillery bin the Hoekse Waard to try to destroy the Moerdijk bridges and sent a team to Rotterdam to blow up the "Willemsbrug". He also ordered the oil reserves of Royal Dutch Shell at Pernis to be set on fire.
The Dutch government asked Winston Churchill for three British divisions to battle the Germans. The new prime minister said he did not have any reserves; however, three British torpedo boats were sent to Lake IJssel. Also, 2nd Welsh Guard battalion was prepared to be sent, but it was too late.
The German command was very happy with the day's events. von Bock had requested another Army Corps. The French were retreating. von Bock decided to follow the French south towards Antwerp. Some forces would be sent to advance north with "254. Infanteriedivision", most of "9. Panzerdivision", and "SS Leibstandarte Adolf Hitler".
In the early morning of 13 May General Winkelman told the Dutch government that there were serious problems. On land the Dutch had been cut off from the Allied front and no major Allied landings were planned by sea. Without support, there was no hope of successful resistance.
German tanks might quickly pass through Rotterdam; Winkelman had already ordered all antitank-guns to be placed around The Hague, to protect the government. However, a collapse of the Dutch defences might still be prevented if attacks could seal off the southern front near Dordrecht and restore the eastern line at the Grebbeberg. Therefore, the cabinet decided to continue the fight, giving the general the power to surrender the Army when he thought he had to.
Queen Wilhelmina was 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 went to England.
The previous evening, the Queen's only child and Princess Juliana, together with her husband and their children, had departed from IJmuiden on "HMS Codrington " for Harwich.