for use on the north bank. On the 20th, however, the 11th Armored Division was ordered to assemble north of Reims. At the same time SHAEF instructed the 6th Airborne Division (British) to move at once by sea to the 21 Army Group area as a preliminary to strengthening the defense on the north bank of the Meuse.
In the meantime the 1st SS Panzer Division was drawing uncomfortably close to the Huy-Dinant sector of the Meuse and the Fifth Panzer Army had ruptured the VIII Corps center. If the German forces continued to hold their pace westward the reinforcements from the United Kingdom would arrive at the Meuse too late. On 19 December, therefore, Field Marshal Montgomery on his own initiative started troops moving south from the 21 Army Group. The British commander had been in process of shifting the weight of his forces to the north in preparation for an offensive in the Rhineland when the Germans unleashed the attack in the Ardennes; indeed Montgomery's southernmost command, the 30 Corps, already had started its advance parties moving north to the Canadian front. But at 1730 on 19 December the 21 Army Group commander ordered General Horrocks to move his 30 Corps from Boxtel, Holland, into the area between Liege and Brussels and gave him the Guards Armoured Division and the 43d, 51st, and 53d Infantry Divisions, as well as three armored brigades.
Because the situation late on the 19th "remained unpleasantly vague," to use Montgomery's own phrase, the British commander undertook emergency measures to bar the Meuse crossings between Liege and Givet while the 30 Corps made its move. Reconnaissance attachments hastily organized from Special Air Services (British) and tank replacement center troops joined the American Communications Zone personnel to set up cover parties at the bridges between Liege and Givet. British armored cars patrolled the north bank of the river between Liege and Namur. The 29th Armoured Brigade, then refitting with new tanks in western Belgium, was ordered to pick up its old tanks and hurry to defend the Namur-Dinant sector. Reports from the First Army at the close of the 19th led Montgomery to believe that there was "little to prevent German armoured cars and reconnaissance elements [from] bounding the Meuse and advancing on Brussels." That night British troops erected barriers and deployed roadblock detachments to protect the capital city, which had been liberated by the Guards Armoured Division on 3 September. 
The rapid deployment of the British screen between Liege and Givet decreased considerably the chance of a surprise crossing on this stretch of the Meuse, and the concentration of the 30 Corps would be accomplished in time to provide a strong counterattack force in the event that the enemy did win a bridgehead. The 120-mile stretch of river from Givet (terminal point of the British line) to Verdun was far less strongly defended than that in the north. It would take approximately a week to bring the 17th Airborne and 11th Armored Divisions from the United Kingdom into the line. Reinforcements moving from the Third and Ninth
 Montgomery, Normandy to the Baltic, p. 280ff; The Memoirs of FieldMarshal Montgomery, p. 276. The latter touches on the Ardennes campaign only lightly.