As Operation Cobra progressively appeared as major success since the D-Day landing by creating new opportunities for a victory, the allied troops have continued to descend upon the ports and beaches of Normandy. This growing quantity of troops and units allowed Allies to create two separate Army Groups :
- 21st British army group was created to cope with the activation on July 23rd of 1st Canadian army, that would reinforce 2nd British army. In fact, on that date, the 1st Canadian army became the first Canadian unit of such a size to be fighting abroad. It would soon play a decisive role in the advance on Falaise, then in the closing of the Falaise gap. The Normandy invasion would mark the first operation in which formations passed from control of the British Army to the Canadian Army, as the 1st British Corps served as part of the First Canadian army.
- The 12th US Army group – created on the basis of the 1st US army and reinforced since August 1st by activation of general’s Patton 3rd Army. Until now, the ebullient general had been participating in deception operation; he commanded the fictional 1st U.S. Army Group, which was supposedly intending to invade France by way of Calais rather than Normandy. This was part of a sophisticated Allied campaign of military deception, codenamed “Operation Fortitude”. After completing this operation, Patton was able to return to another mission, more in conformity with his true nature. In just two weeks, the furious charge of his armoured divisions would lead him to the banks of the Seine.
The corridor, which opened in Avranches, represented a lethal threat to the German army in Normandy. Indeed, following the 1st Army, entrusted meanwhile to Hodges (with Bradley himself being appointed in command of the 12th Army Group), Gen. Patton’s 3rd Army had engulfed in the breach with no less than 7 divisions.
The situation started to evolve very quickly: meeting a very limited resistance, the Americans were pushing in the direction of Brittany and the Loire Valley. The most serious threat from the German point of view was the 15th Army Corps, which took direction East, on Laval, from where it could roll on their backs…
Under these circumstances, Hitler had two options. First, to retreat on a Seine-Switzerland defensive line, and likely to offer coherent defensive possibilities. The second, to try to fill the breach by means of a military attack aimed on Avranches in order to reach the bay of Mont Saint Michel. In opposition to the opinion of his Generals, who realistically suggested the first option, Hitler refused to allow any retreat and retained the second alternative.
Von Kluge, who strongly opposed to Hitler’s project, evaluated its chances for success as close to zero and drafted the simple, if not simplistic plan. He opted for a surprise attack that would be carried out at night and would break up American lines, thus allowing his meager forces to advance about forty kilometers. Fully aware of the fact that number of Allied troops penetrating on the back of his army was increasing with each passing day, von Kluge decided not to wait for hypothetical reinforcements, but started the attack on August 6th, at midnight.
Consequently, east of Mortain, he gathered together in record time as many elements of his elite armoured units as he possible could: SS divisions Leibstandarte and Das Reich; elements of the 116th PzD; remainders of 2nd PzD, and a handle of survivors of the Panzer Lehr.
Even before it commenced, the planned operation was seriously compromised for two main reasons:
- First, the Allies had deciphered the coded messages identifying the movements of German troops and disclosing the forthcoming attacks; consequently, the effect of surprise was eliminated.
- Second, the offensive started with only a fraction of the troops, which were supposed to take part in the action: a large detachment of Leibstandarte had not arrived, while another part suffered from allied air raids, losing more than one quarter of initial manpower during its movement to the front. Last, the commander of the 116th PzD was so convinced of the madness of the assault that he never even issued orders to make its tank battalion to arrive on the battlefield…
On August 6th, at midnight, the German forces, organized in two military columns, launched 150 tanks against American lines. In spite of the absence of artillery barrage, the elements of the 2nd SS PzD Das Reich (southern column) quickly hustled the 30th US infantry division and isolated one battalion, which would have to fight encircled by enemy during several days on the Coast 314.
Supported by night bombings launched by the Luftwaffe, present for once, the Germans succeeded in capturing Mortain. To the North, the second column, made up mainly of the 2nd PzD, met even weaker resistance. Indeed, it drove the Americans back from the field by nearly 10 kilometers, but then faced the 9th Infantry Division about 3 km short of its objective. The arrival of long awaited elements of the 1st SS PzD did not allow for additional advance in the morning.
At midday, the thick fog, which blocked any action of allied aviation, started to clear away. Consequently, the successive raids of the Typhoon Jabos prevented the continuation of the German offensive, as salvos of rockets destroyed tanks and armoured vehicles exposed on the open plains. In a couple of hours, von Kluge lost about half of his tanks engaged in the operation. Additionally, he lost a large part of his last elite SS troops. The German counter-offensive had failed.
In spite of common sense, Hitler still denied his commanders in Normandy the right to retreat to the East by ordering his armoured divisions to hold their positions, even though they were short on ammunition and fuel. The engagements were thus continued during following days, but it was now clear that the German forces ran into a dead end. By moving their best troops to the western salient of the front, they did not leave much, but a thin curtain of troops in the North. Operation Totalize, launched by the Canadians on the road to Falaise, was aimed at taking advantage of these circumstances.