Operation Cobra, 25-31 July 1944

Operation Cobra (25-31 July 1944) saw the decisive breakthrough in Normandy, after more than a month of attritional fighting and slow progress, and saw Bradley’s US 1st Army break the western end of the German line, allowing the Allied armour to break out and dash east towards the Seine, trapping a large part of the Germany army in the Falaise pocket.

The American Plan

Montgomery’s overall plan for Normandy had always been for the British and Canadians to pull most of the German armour into a battle in the eastern part of the beachhead, while the Americans would make the main breakthrough in the west. However he didn’t always explain his plans well, and the prolonged battle for Caen began to worry Eisenhower. At the same time American progress in the west was slower than expected. The bocage country turned out to be an ideal defensive landscape, filled with small fields surrounded by thick hedgerows on earthen banks. The advance north up the Cotentin Peninsula and the capture of Cherbourg had gone fairly quickly, but when the main effort turned south the Americans made very limited progress. General Bradley, commander of the 1st Army, had wanted to reach the road from St. Lo to Coutances before he attempted to break through, but progress was far too slow. Saint Lo fell on 18 July, but further to the west progress was limited.

Bradley decided to alter his plans. He would now use the Saint Lo to Periers road as his starting point, (Periers is about ten miles to the north of Coutances). The attack would be preceded by a massive air attack, designed to knock a hole in the German defences. General Collins’ 7th Corps would attack through the gap, and push south. Originally the plan included a turn to the west to reach the coast to trap the forces that were facing General Middleton’s 8th Corps, but this was cancelled to avoid any accidental clashes between the two US corps. Once the German lines had been broken the armour would push south towards Avranches, at the junction between Normandy and Brittany. The extra space created by this advance would allow General Patton’s 3rd Army to be activated, and provide a base for the attack east towards the Seine.

In the initial plan the 7th Corps was given three infantry and two armoured divisions for the attack, and its front was reduced in width to four and a half miles. Two of the infantry divisions, the 9th and 30th, were to carry out the initial attack, and capture Marigny and St. Gilles on the flanks of the breakthrough. The 2nd and 3rd Armoured Divisions were then to advance through the three mile wide gap between Marigny and St. Gilles and exploit the breakthrough. The motorised 1st Division was to act as a reserve for the two armoured divisions. The main axis of exploitation was to be west towards the coast near Coutances, with the 3rd Armoured pushing west while the 2nd Armoured fanned out to the south-west to protect the left flank of this move. This would trap some German forces, which would be attacked by the 8th Corps. The corps staff then modified the plan, requesting the 4th Infantry Division to support the initial attack and altering the direction of the armoured assault. The 1st Division and part of the 3rd Armoured were to push directly west towards Coutances, with the rest of the 3rd Armoured following the original longer route to the south of the town. The 2nd Armoured would still protect the left flank, but its lines were extended further to the east. The entire corps was to stop a short distance from the west coast to give the 8th Corps a corridor to attack down.

The attack was to be supported by a massive aerial attack, involving the tactical aircraft of the 9th Air Force and the strategic bombers of 8th Air Force. This was so important to Bradley that he went to Britain on 19 July to discuss his plan personally with the air commanders. Despite this effort, Bradley didn’t entirely get his way. He wanted a massive attack to be carried out on an area 3.5 miles wide and 1.5 miles deep, on the southern side of the Saint-Lo to Periers road. He wanted light bombs to be used to avoid creating a cratered landscape that would slow down the advance. He would withdraw his troops by 800 yards. Finally he wanted to bombers to attack from the west, flying parallel to the front line, using the main road as an obvious navigational aide. The air commanders insisted on attacking from the north. Their logic was that if they attacked from the west they would hit the narrow 1.5 mile wide side of the target area, so would have to fly in a narrow, long formation. It would thus take longer to hit the entire area. If they attacked from the north, they would be able to attack in a wide, shallow formation, and cover almost three times the area in any set time. They also wanted the ground troops to be pulled back further.

The German Forces

The western part of the German line in Normandy was defended by the Seventh Army, commanded by General Hausser. He only had two armoured divisions – the 2nd SS Panzer Division and Panzer Lehr – and both of those units had already been committed to the front line. To the east Panzer Group West had briefly been able to withdraw some of its panzer divisions from the front line to form a reserve, but had then had been forced to throw them back into the line by Operation Goodwood.

The Cobra front was held by the LXXXIV Corps, which defended a line that ran generally along the highway from St. Lo west/ north west through Periers, reaching the west coast at Lessay, eleven miles to the north of Coutances. This corps commanded an impressive array of divisions, but many of them were only fragments.

In the west the remains of the 243rd Division held the coastal area around Lessay.

On their right was the 91st Division, which also controlled the survivors from the 77th Division and a kampfgruppe from the 265th Division.

Next came the 2nd SS Panzer Division, supported by the 6th Parachute Regiment and part of the 17th SS Panzergrenadier Division, defending the Periers area.

On their right was one regiment from the 5th Parachute Division, recently arrived from Brittany.

Next came Panzer Lehr, supported by 450 troops from a Kampfgruppe from the 275th Division and a regiment from the 5th Parachute Division. Their front ran east from the Taute River to within two miles of the Vire.

The two miles west of the Vire felt into the II Parachute Corps front, and were held by 650 troops from the 352nd Division.

The Germans had very few reserves behind this line. The 352nd Division was south of Periers. Two regiments from the 275th Division, fresh from Brittany, were behind Panzer Lehr. Two infantry companies and two tank companies from the 2nd SS Panzer made up the only mobile reserves.

The Germans had around 30,000 men on the front facing 7th Corps, but only 5,000 or so were on the key part of the front between the Taute and the Vire. Around 3,200 men from Panzer Lehr and its supporting units were directly in the path of the upcoming attack. Panzer Lehr’s main line of resistance was to the south of the Periers to St. Lo highway, with a few outposts north of the road, and some limited reserves just to the south of the main forces.

24 July

Unfortunately the heavy bomber attacks didn’t go according to plan. The weather caused a delay. On 24 July Leigh-Mallory finally ordered the attack to take place, but then carried out a reconnaissance flight in person, found that the weather was poor, and cancelled the attack. Not all of the aircraft involved received the order, and 317 of the original 1,586 bombers still attacked. There were two incidents during this attack, both made worse by the US policy of using a master bomber who was automatically copied by the aircraft behind him. This policy had improved the overall accuracy of 8th Air Force bombers, but didn’t work so well when operating close to friendly forces. On 24 July one lead bombardier suffered from problems with his bomb release switch, and dropped his bombs early. He was followed by the rest of his squadron, and the bombs hit US troops, killing 16 and wounding 60. In a second incident the Allied-held Chapelle airfield was hit, killing 4 and wounding 14 from the 404th Fighter Group. The problem was made worse by the decision to fly across the American front lines, which meant that any early release would hit friendly troops.

The limited bombing caught Collins by surprise, as he had been informed that the attack had been postponed. In the aftermath of the bombing he ordered his men to retake the ground they had abandoned earlier in the day. The Germans fought back, and progress was slow. However this also caused some over-confidence on the German side, where they believed they had stopped a genuine offensive. The Germans also used up many of their limited supplies in the fighting on 24 July.

25 July

The start of Operation Cobra was postponed until the following day, but once again there were some problems with the heavy bombers. The tactical aircraft of 9th Air Force carried out a successful raid, but once again there were problems with the heavies. One lead bombardier released his bombs early after setting his bomb site incorrectly. As a result twelve B-24s dropped 470 100lb bombs on US troops. Another bombardier mistook a flash from American artillery for a target marker, and dropped his bombs. His squadron dropped 352 250lb bombs in the same area as the first incident. Another squadron bombed early when their lead bombardier followed the wing commander instead of the group commander. A total of 111 men were killed and 490 were wounded. Amongst the dead was Lt General J. McNair, the commander of the home based US Ground Forces and Patton’s replacement as the commander of the fake 1st US Army Group.

However the Germans had suffered much worse casualties. Panzer Lehr reported losing 25 tanks, 10 assault guns and over 1,000 men, a third of the total front line troops. Many of the division’s surviving tanks were bogged down. This was one of only two panzer divisions facing the Americans, so the damage it suffered greatly weakened the German defences.

Once the bombing was over the American attack began. However progress on 25 July was slower than had been expected. In some cases this was because the attacking units had been badly shaken by the short bombing. By the end of the day Collins’ three divisions had only just managed to cross the Periers- Saint Lo road, and many American commanders reported that the air attack had been ineffective.

The targets for the day were Marigny and St. Gilles, with the 9th Division attacking Marigny in the west and the 30th Division attacking St. Gilles in the east.

On the 9th Division front the limited German outposts north of the road were quickly overcome, but were slowed down south of the road by pockets of German troops who had survived the bombing. The Division’s task was then to turn west to secure the right flank of the breakthrough, but this brought them up against units who hadn’t been hit by the bombing, and progress was limited.

In the centre one regiment from the 4th Division attacked. One of its battalions pushed south for a mile and a half, while the other came close to la Chapelle-en-Juger, just over one mile south of the road.

On the 30th Division front the terrain and isolated German strong points slowed the advance, but the division did capture Hebecrevon by midnight at the end of the day. This still meant that they were only half way to their target for the day.

The air and ground attacks had actually caused far more damage than the Americans realised. Panzer Lehr was on its last legs, and there was now a gap in the German line. On the German side communications had been badly affected, and it wasn’t clear how much damage had been done. General Hausser, command of the VII Army and General von Choltitz, commander of the 84th Corps, each sent a regiment to reinforce the division, but one of these was knocked out by American fighter bombers on its way. Only Kluge realised how close the Americans were to success, and late on 25 July reported that the ‘front had burst’. However he spent the day on the Caen front, attracted by Operation Spring, a costly Canadian attack.

26 July

On 26 July 7th Corps started to make more rapid progress, advancing five miles south of the road. General Collins had been faced with a crucial decision late on 25 July. Although there had been pockets of German resistance, it had been less organised than normal. This could mean that the bombing and the day’s fighting had smashed the German main line, or that the real main line of resistance was actually further south. If the first was the case then it was time to commit the American armour. If the second was the case then committing the armour might cause the sort of congestion that had stifled earlier attacks, or even leave the Americans exposed to a counterattack. Collins decided to take a gamble, and during the afternoon of 25 July ordered his armour to join the battle on 26 July.

On the German side General Choltitz committed a regiment from his corps reserve, the 353rd Division, and ordered it to move east from Periers to la Chapelle-en-Juger. At army level Hausser had the same idea, and ordered a regiment from the 275th Division to move north-west from Canisy to la Chapelle. Both men were hoping that their reinforcements would allow them to seal off the breakthrough. However the regiment from the 275th was almost destroyed by fighter bombers as it approached the battlefield. Throughout the day the Germans suffered from the breakdown in their communications caused by the bombing, meaning that Choltitz and Hausser were both reacting to situations that were no longer relevant.

At the western end of the breakthrough the 5th Parachute Division managed to prevent the Americans making any progress. However the US 330th Infantry, fighting on that flank, did manage to open up the Marigny road for the American armoured divisions to use.

In the centre the 4th Division captured la Chapelle-en-Juger early in the day, making the Germans plans to use it as part of a new defensive line obsolete. During the afternoon they were able to push south three miles, destroying part of the 353rd Division and forcing Panzer Lehr’s artillery to flee.

At the eastern end the 352nd Division (II Parachute Corps) was unable to hold the western banks of the Vire, although they held on for much of the day. By the end of the day the US 30th Division had advanced three miles from their initial positions, and had reached the Vire two miles west of St. Lo.

At the same time two armoured columns were committed to the battle, one with orders to capture Marigny and the other to take St. Gilles. They were each supported by 200 fighter-bombers. The attack on Marigny was carried out by the 1st Infantry Division and Combat Command B from the 3rd Armoured Division. The column got close to Marigny before running into more organised resistance, from the 353rd Division and two companies from the 2nd SS Panzer Division. By the end of the day part of the force was on the northern edge of the town, and another column one mile to the west. At higher levels the Americans mistakenly believed that Marigny had been taken, and the column was ordered to attack west overnight, but its commander, General Huebner, knew that the time wasn’t right and paused for the evening.

On the eastern flank the 2nd Armoured Division was to take St. Gilles, and protect the left flank of the attack towards Coutances. On this flank the German resistance was much weaker, and the division captured St. Gilles in the mid-afternoon. Combat Command A from the division continued to push south, advancing south along the road from St. Gilles to Canisy. This had been in the Panzer Lehr zone, and was now almost undefended. By the end of the day the column had taken Canisy, and the combat command then split up with one part taking St. Samson-de-Bonfosse and the other a key junction north of le Mesnil-Herman during the night.  

To their west the 8th Corps also began to make progress, attacking on a four division front. Their task was to reach the Lassay-Periers highway, cross the road and advance about half way to Coutances to apply pressure to the Germans on the coast. On the first day of the attack the Germans held on to most of their positions, although the 8th Corps did reach part of the highway. However this progress was enough to prevent Hausser from moving the 2nd SS Panzer Division from the coast to try and plug the gap. Hausser wanted to withdraw to Coutances in the coastal section, and start the construction of a new line from there to la Chapelle-en-Juger, but Kluge restricted him to a smaller retreat.

27 July

The German position began to collapse on 27 July. American infantry kept on pushing south, attacking over night on 26-27 July. Mobile columns captured Marigny and St Gilles, close to the Saint-Lo to Coutances road, and then turned west towards Coutances.

In the west infantry from the 1st Division was given the task of clearing Marigny, while the attached CCB from the 3rd Armoured Division was ordered to push west towards Coutances. Their task was to capture a series of hills, each close to a village – first Camprond, then Cambernon and finally Monthuchon. The last of these was just to the north of Coutances. By midafternoon the tanks had taken Camprond, while the infantry had cleared Marigny. By the end of the day the 1st Division had pushed west on a three mile wide front, and were five miles to the west of Marigny, but they had only taken the first of their three objectives – Camprond and the nearby hill. On the following day the hills at Cambernon and Monthuchon were transferred to the 8th Corps, although CCB continued to push that way.

In the east CCA of the 2nd Armoured Division reached le Mensil-Harman and captured the key Hill 183. At that point its role in the battle came to an end. On the same day CCB was committed to the battle. Their first task was to advance to Canisy, and then head south-west to form a defensive line to protect against any German counterattack from the south. By about 3pm they had reached Canisy, but their orders were then changed. Their new role was to push much further to the south-west and try to reach Cerences and Brehal and the west coast of the Cotentin, to block the German troops retreating along the west coast. For the rest of the afternoon the command pushed on for seven miles, reaching Notre-Dame-de-Cenilly, seven miles from Canisy. At one point the advancing Americans passed through the same village that General Bayerlein, commander of Panzer Lehr, was using as his HQ (along with the 275th Division), although the Americans passed on without realising how close they had come to capturing him. This convinced Bayerlein to report that Panzer Lehr had been ‘finally annihilated’, and was the first clear demonstration that the Americans had indeed broken through the German lines.

In the centre the bulk of the 3rd Armoured Division was committed to the battle, with the task of pushing south/ south-west to Cerisy-la-Salle, then turn west. However the division was help up by several German strongpoints that its tanks struggled to bypass, and ended the day with its leading troops three miles north of Cerisy.

Allied Troops at Coutances, 1944
Allied Troops at Coutances, 1944

Progress was slower than expected, but this was largely because the Germans had decided to retreat on the coast. In order to protect those troops from the Americans pushing west, a new defensive line facing east was set up, and this held up the 1st Division advance during 27 July. During the day the Germans realised that their initial plan, for a limited retreat on the coast to form a new defensive line around Coutances, was no longer valid. However their new plans all depended on Panzer Lehr being able to hold part of the new line, and that division was no longer an effective unit.

On the 8th Corps front it looked at first as if the Germans were still going to defend their front line, but when the corps began a full scale assault they discovered that they had retreated, leaving behind extensive minefields. The corps was able to make steady progress, capturing Periers and the full length of the Lessay-Periers highway, but the Germans had successfully retreated, so they only took 100 prisoners.

28 July

On the German side the troops on the coast – elements of the 243rd, 265th, 77th, 91st and 5th Parachute Divisions continued to retreat south, protected by part of the 2nd SS Panzer Division, which now held a 3 mile long line from Cambernon (to the north-east of Coutances) south-east to Savigny, east of the town.

On the 7th Corps right CCB of the 3rd Armoured Division continued to push towards the hills, and captured Cambernon by noon. They were then given permission to push on to Monthuchon, only to discover that 8th Corps had already taken it. The 1st Infantry advance ran into the 2nd SS Panzer Division line and were held up until CCB turned back and attacked from the north-west. The German line then collapsed. 

The rest of 3rd Armoured Division once again made slow progress during the day. The division adopted a new plan, in which the three elements of CCA, which were strung out in a line on the road to Cerisy-la-Salle, would each begin the attack west from wherever they had reached. The southernmost task force would bypass Cerisy-la-Salle and advance towards Montpinchon, the next village to the west. The middle force would take over the attack on Cerisy-la-Salle. Finally the trailing force would attack west from Carantilly towards Coutances. None of these columns made as much progress as hoped – in the north the attack from Carantilly ran into a strongpoint four miles west at Savigny, while the central and southern forces were held up by troops from the 17th SS Panzergrenadier Division, which had only just arrived at Cerisy.

To the south of Coutances CCB of the 2nd Armoured Division continued to push west. The order to push all the way to the coast was cancelled, and instead they were to stop at Lengronne, on the main road south from Coutances. They reached their targets fairly easily, and prepared to stop any Germans coming from the north.

On the 8th Corps front the original target line, half way to Coutances, was removed and the corps allowed to push on to the south. All four divisions were able to make rapid progress through almost undefended countryside, with the two divisions on the right reaching the area of Coutances and the two on the left making contact with the 1st Division, coming from the east. However once again very few prisoners were taken as the Germans continued to retreat on the coast.

However the Germans had not yet escaped from the trap, and by the end of the day it became clear that a large number of troops were trapped around Montpinchon and Roncey, to the east and south-east of Coutances. They were now surrounded by the 1st Infantry and attacked by CCB to the north, the rest of 3rd Armoured to the east and CCB from 2nd Armoured to the south. During the day General Tychsen, commander of the 2nd SS Panzer Division, was killed in combat, and Hausser was fired on by an armoured car. The Germans within the Roncey pocket prepared to break out, but while the troops within prepared for an attack south toward Brehal, Hausser ordered them to try and attack south-east to join the forces that Kluge was preparing for a counterattack. The problem with Hausser’s plan was that it would leave a very weakly defended gap at the western end of the German lines in Normandy. Kluge reacted violently, and issued his own orders. The trapped troops were to mount a holding attack to allow LXXXIV to retreat south along the coast. They would then form a new line running inland from Brehal. At the same time Kluge would use two fresh panzer divisions to attack west towards Percy (somewhat to the south of the current American positions). Kluge’s orders reached Hausser, but he no longer had any phone lines to Choltitz, so had to send a courier. He arrived at Choltitz’s HQ at midnight, by which time it was too late to change the plans.

28 July also saw the start of Operation Bluecoat, a British attack in the gap between Caen and Saint Lo, which saw two British corps push south and helped prevent the Germans moving reinforcements to the west.

29 July

On the 3rd Armoured front the northern task force finally eliminated the German pocket at Savigny, while the 17th SS Panzergrenadiers had withdrawn overnight, allowing the central and southern task forces to push on to the road from Coutances to Gavray, putting them south of Coutances.

On the German side a mixed force of troops from the 2nd SS Panzer Division, 17th SS Engineer Battalion, 6th Parachute Regiment and the survivors from the 17th SS Panzer Grenadier Division were now assembled around Roncey. Just before dawn they made their first attempt at a breakout, attacking a crossroads to the south-west of Notre-Dame-de-Cenilly. This was the start of a larger attack, but despite some minor successes the Germans were unable to break through. The 2nd Armoured Division line held. During the day Allied fighter bombers attacked the German troops trapped within the Roncey pocket. After the fighting was over more than 100 damaged tanks were found within the pocket. During the night of 29-30 July the Germans made another attempt to break through the lines. They had a minor success at St. Denis-le-Gast, but otherwise made little progress. By 30 July the pocket had been destroyed.

Technically this marked the end of Operation Cobra. The breakthrough had been achieved, and the German position in the Cotentin had been destroyed. There was now a gap in the German lines between Percy and the west coast, about fifteen miles wide, held by the remnants of the 91st Division. The Americans were now in a position to begin the dramatic breakout that ended the stalemate in Normandy. 

The Break Out

By 30 July the Roncey pocket had been destroyed, and the road to Avranches was open. The 91st Division’s line was overrun by the afternoon of 30 July. At Granville the staff of a naval coast artillery battery abandoned the gun emplacement and retreated towards Avranches. By the end of 30 July both Choltitz’x LXXXIV Corps HQ and Hausser’s advanced command post were behind American lines!

The two US corps continued to push on. Collins attacked towards the See river and the Avranches to Mortain road. Middleton attacked from Coutances towards Avranches. At one point a US column passed within a few yards of Hausser’s command post, as the German front continued to collapse. The first US troops reached Avranches on the evening of 30 July, actually reaching the town ahead of the Germans! Fighting only broke out after retreating German troops attempted to enter the town, unaware it had fallen.

On 31 July Kluge was still largely in the dark. He was aware that the Americans had taken Avranches, but otherwise reported that the situation was ‘completely unclear’, and that the ‘Americans have ripped open the whole western front’.

In the last six days of July the US 1st Army had taken 20,000 prisoners, and had broken the German lines in Normandy.


Operation Cobra transformed the situation in Normandy. Even Hitler had to admit that the battle was lost, and began to plan for a withdrawal to the Westwall defences. However he was aware that it would take at least six weeks to turn the Westwall into a real defensive position. He ordered the troops in France to destroy any transport links as they retreated, and for the garrisons of a series of fortress ports to fight to the last man. Brittany was abandoned apart from the ports. This was all fairly sensible, but Hitler also still hoped he could stop the breakthrough. He thus ordered Kluge to carry out a counterattack towards Avranches, Operation Luttich. If the US breakthrough could be stopped, then there was a chance that a new defensive line could be created, this time running from the coast south of Avranches north-east to Caen. However the result was a disaster for the Germans. Operation Luttich, or the battle of Mortain, failed to achieve any of its objectives. The German attack was stopped without imposing any real delay on the main American advance, and all it achieved was to move a large part of the German army in Normandy further into a trap. The shattered remains of the German army would soon have to try and escape through the Falaise Gap, and although many of the men escaped, almost none of the heavy equipment was saved.

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How to cite this article: Rickard, J (7 September 2020), Operation Cobra, 25-31 July 1944 , http://www.historyofwar.org/articles/operation_cobra.html

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