was to form the vanguard of the ground advance into the Netherlands, tasked with capturing a vital bridge over the IJssel, attacking the main line of defense at the Grebbeberg (the Grebbeline), and linking up with the Fallschirmjäger of Generaloberst Kurt Student's airborne forces, the 7.Flieger-Division and the 22.Luftlande-Infanterie-Division. Fall Gelb—the invasion of France and the Low Countries—was launched on 10 May 1940. On that day, the LSSAH crossed the Dutch border, covered over , and secured a crossing over the IJssel near Zutphen after discovering that their target bridge had been destroyed. Over the next four days, the LSSAH covered over , and upon entering Rotterdam, several of its soldiers accidentally shot at and seriously wounded General Student. After the surrender of Rotterdam, the LSSAH left for The Hague, which they reached on 15 May, after capturing 3,500 Dutch soldiers as prisoners of war. After the surrender of the Netherlands on 15 May, the regiment was then moved south to France. After the British counterattack at Arras, the LSSAH, along with the SS-Verfügungs-Division, were moved to hold the perimeter around Dunkirk and reduce the size of the pocket containing the encircled British Expeditionary Force and French forces. The LSSAH took up a position 15 miles south west of Dunkirk along the line of the Aa Canal, facing the Allied defensive line near Watten. That night the OKW ordered the advance to halt, with the British Expeditionary Force trapped. The LSSAH paused for the night. However, on the following day of 25 May, in defiance of Hitler's orders, Dietrich ordered his 3rd battalion to cross the canal and take the Wattenberg Heights beyond, where British artillery observers were putting the regiment at risk. They assaulted the heights and drove the observers off. Instead of being censured for his act of defiance, Dietrich was awarded the Knight's Cross of the Iron Cross. On 26 May the German advance resumed. By 28 May the LSSAH had taken the village of Wormhout, only ten miles from Dunkirk. After their surrender, soldiers from the 2nd Battalion, Royal Warwickshire Regiment, along with some other units (including French soldiers) were taken to a barn in La Plaine au Bois near Wormhout and Esquelbecq. It was there that troops of the LSSAH 2nd battalion, under the command of SS-Hauptsturmführer Wilhelm Mohnke committed the Wormhoudt massacre, where 80 British and French prisoners of war were killed. Although it