At Valkenburg the Dutch had managed to isolate the Germans in the village near the airfield. The considerable Dutch successes of the first day would not be continued on the 11th.
The Germans [commanded by Oberst Heyser] had managed to safeguard the majority of their troops from slaughter or captivity and as such a very considerable force prepared its positions in and around the village against anticipated Dutch offensive actions. The airfield was entirely in Dutch hands. It had been bombed by both British [these planes had been underway while the Dutch had already succeeded chasing off the German occupation] and German strike planes after the recapture, but yet the Dutch forces did not leave the vicinity of the base again.
Situation in the village
The Germans held about 300 Dutch troops prisoner in the village. These men had been gathered in a church in the centre of the village. In an emergency hospital [in fact a school building] about 200 wounded soldiers [Dutch and German] were taken care of by both Dutch and German doctors.
The village itself had not been evacuated. Without any exception all these people and buildings were exposed to the intensive Dutch artillery fire than regularly rained down on the village in a number of barrages. To both the civilian population [and POW's] and the occupying German force the shelling of the Dutch artillery seemed an ever lasting ordeal that caused severe psychological effect as well as many casualties.
The Dutch actions
The Dutch forces were concentrated in and around Katwijk and some smaller forces were located near Leiden and Wassenaar. Two artillery battalions were assigned as support.
Lieutenant-Colonel Buurman was the commanding officer of 4RI and had been assigned the instruction to retake Valkenburg from the Germans. As we saw before, he had also become the commanding officer in charge of the dune-sweep and therefore he and his staff were fully occupied.
The forces that he had under his effective command had mainly been occupied with the operation in the dunes. Other units had been assigned defensive positions around the German pockets at Valkenburg. As such only a tactical manoeuvre formation of a little more than a company had been left at the Lt-Col's disposal to retake Valkenburg, yet he did not consider sitting back. He realised that the Germans would benefit from a prolonged pressure-realise on their bridgehead and therefore Buurman decided that some offensive action had to be developed.
Buurman ordered a company-size force to enter Valkenburg from the north. One battery of 12 cm howitzers unleashed a creeping barrage, after which the men went forward. Although the company met plenty opposition, they managed to reach the northern outskirts of Valkenburg. When the spearhead had even managed to reach the village centre it was suddenly treated on yet another - but unexpected - artillery barrage. This series of volleys came from Oegstgeest, where the 7,5 cm guns of 6.RA had opened up, totally unaware of the other Dutch manoeuvre. The infantry men were forced to retreat. They had suffered three dead and six wounded [all from German defence though]. A bitter outcome of a promising action, all due poor command and control once again.
In the late afternoon another assault on the village was planned; this time with the newly arrived 1st Battalion of 9.RI. This battalion had experienced a tragedy the day before. When it had been directed from Haarlem to Leiden, one of the busses and some trucks carrying two sections of infantry - of the 1st Company - had been hit by three bombs from a German bomber. No less than 22 men had been killed and 30 wounded.
The 9.RI assault would be directed along the Oude Rijn [Old Rhine] river, which ran north by northeast from Valkenburg to Katwijk. Two companies would proceed beside each other from Katwijk south to Valkenburg. One company would attack along the road that entered the village to the north. The other company was ordered to negotiate two small canals and attack Valkenburg from the northwest. Two sections of heavy machineguns were available to cover the assault by taking a north-eastern position on the east side of the Oude Rijn. The attack was supported by three batteries of 12 cm howitzers. A text-book assault so to say.
At 1800 hours the artillery opened up. The barrage crept through the northern outskirts of the village to the centre, where it caused much destruction. The church in which the Dutch POW's had been assembled was hit by at least three grenades and panic amongst the men made several storm out. The Germans forced them back in! Meanwhile the infantry moved forward, but was soon forced to hit the deck for intensive German machinegun fire pinned them down.
The Germans in Valkenburg fired from every weapon available, and when also the Luftwaffe contributed by means of a number of strafing Messerschmitts it all became too much. The attack stalled completely and after sunset the assaulting troops moved away from Valkenburg.
To the southeast the Dutch forces had prepared to contribute to the assault that was planned for 1800 hours. The troops at the Haagse Schouw [Leiden] had received reinforcements of three armoured cars [Landsverk] from the Veluwe. They were however very surprised not to be included in the attack-plans and besides some patrolling activity they just held their positions. These three armoured cars could have contributed to a possible success, since the Germans lacked AT guns in Valkenburg. It was not to be though.
A number of individual actions by units around Valkenburg were developed. Some of these actions were rather well prepared, others without thoroughly prepared plans. Here and there some German outposts were driven off or forced to surrender. But that was it. The entire battle lacked any thorough cross-unit planning from 1st Corps, and as such the superior Dutch force around Valkenburg was unable to gain any serious progress during the second day.
During this day opportunities had been wasted, mainly by poor coordination that could only be partially blamed on the responsible authorities. The most important challenge remained the coordination of actions in a sector that lacked any communication facilities to gain a current and accurate battlefield awareness by any of the active commanders. None of the senior officers had an accurate overall picture. An affair that was clear proof of lacking coordination from the divisional and corps staffs.
The Dutch lost 10 men KIA this day around Valkenburg, of which 6 men were killed as POW's inside the church in the village as a result of the 'friendly' artillery. Three men of 9.RI had been killed during the action in the morning. The Germans lost 9 KIA in the village.