World War II: Operation Cobra and Breakout from Normandy

American armored and infantry forces pass through the battered town of Coutances, France. Photograph Courtesy of the US Army

Operation Cobra was conducted from July 25 to 31, 1944, during World War II (1939-1945). After the Allied landings in Normandy, commanders began to formulate a plan to push out from the beachhead. Initial efforts were hampered by the need to take the city of Caen in the east and the dense hedgerow country in the west. Seeking to launch a major breakout, General Omar Bradley sought to focus the Allies' efforts on a narrow front west of St. Lô.

Moving forward on July 25 after the area had been heavy bombed, American troops achieved a breakthrough. By the third day, most organized German resistance had been overcome and the speed of the advance increased. Coupled with assaults by British and Canadian forces, Operation Cobra led to the collapse of the German position in Normandy.


Landing in Normandy on D-Day (June 6, 1944), Allied forces quickly consolidated their foothold in France. Pushing inland, American forces in the west encountered difficulty negotiating the bocage of Normandy. Hampered by this vast network of hedgerows, their advance was slow. As June passed, their greatest successes came on the Cotentin Peninsula where troops secured the key port of Cherbourg. To the east, British and Canadian forces fared little better as they sought to capture the city of Caen. Grappling with the Germans, the Allied efforts around the city succeeded drawing the bulk of the enemy armor to that sector (Map).

Eager to break the deadlock and begin mobile warfare, Allied leaders began planning for a breakout from the Normandy beachhead. On July 10, following the capture of the northern part of Caen, the commander of the 21st Army Group, Field Marshal Sir Bernard Montgomery, met with General Omar Bradley, commander of the US First Army, and Lieutenant General Sir Miles Dempsey, commander of the British Second Army, to discuss their options. Admitting progress was slow on his front, Bradley put forward a breakout plan dubbed Operation Cobra which he hoped to launch on July 18.

Lt. Gen. Omar Bradley (center) during World War II
Lt. Gen. Omar Bradley (center) with Lt. General George S. Patton (left) and General Sir Bernard Montgomery (right) at 21st Army Group HQ, Normandy, 7 July 1944. Public Domain


Calling for a massive offensive to the west of Saint-Lô, Operation Cobra was approved by Montgomery who also directed Dempsey to keep pressing around Caen to hold the German armor in place. To create the breakthrough, Bradley intended to focus the advance on a 7,000 yard stretch of the front south of the Saint-Lô–Periers Road. Prior to the attack an area measuring 6,000 × 2,200 yards would be subjected to heavy aerial bombardment. With the conclusion of the air strikes, the 9th and 30th Infantry Divisions from Major General J. Lawton Collins' VII Corps would move forward opening a breach in the German lines.

These units would then hold the flanks while the 1st Infantry and 2nd Armored Divisions drove through the gap. They were to be followed by a five or six division exploitation force. If successful, Operation Cobra would allow American forces to escape the bocage and cut off the Brittany peninsula. To support Operation Cobra, Dempsey commenced Operations Goodwood and Atlantic on July 18. Though these took substantial casualties, they succeeded in capturing the remainder of Caen and forced the Germans to retain seven of the nine panzer divisions in Normandy opposite the British.

Armies & Commanders


  • Field Marshal Bernard Montgomery
  • General Omar Bradley
  • 11 divisions


  • Field Marshal Gunther von Kluge
  • Colonel General Paul Hausser
  • 8 divisions

Moving Forward

Though the British operations commenced on July 18, Bradley elected to delay several days due to poor weather over the battlefield. On July 24, Allied aircraft began striking the target area despite questionable weather. As a result, they accidentally inflicted around 150 friendly fire casualties. Operation Cobra finally moved forward the next morning with over 3,000 aircraft striking the front. Friendly fire continued to be an issue as the attacks inflicted a further 600 friendly fire casualties as well as killed Lieutenant General Leslie McNair (Map).

Advancing around 11:00 AM, Lawton's men were slowed by surprisingly stiff German resistance and numerous strong points. Though they gained only 2,200 yards on July 25, the mood in the Allied high command remained optimistic and the 2nd Armored and 1st Infantry Divisions joined the assault the next day. They were further supported by VIII Corps which began attacking German positions to the west. Fighting remained heavy on the 26th but began to wane on the 27th as German forces began retreating in the face of the Allied advance (Map).

Breaking Out

Driving south, German resistance was scattered and American troops captured Coutances on July 28 though they endured heavy fighting east of the town. Seeking to stabilize the situation, the German commander, Field Marshal Gunther von Kluge, began directing reinforcements west. These were intercepted by XIX Corps which had begun advancing on VII Corps' left. Encountering the 2nd and 116th Panzer Divisions, XIX Corps became embroiled in heavy combat, but succeeded in shielding the American advance to the west. German efforts were repeatedly frustrated by Allied fighter bombers which swarmed over the area.

American troops in Coutances, 1944
U.S. tanks pass through a wrecked street in Coutances, Normandy in their drive to the sea beyond the town. National Archives and Records Admininstration

With the Americans advancing along the coast, Montgomery directed Dempsey to begin Operation Bluecoat which called for an advance from Caumont towards Vire. With this he sought to hold German armor in the east while protecting Cobra's flank. As British forces rolled forward, American troops captured the key town of Avranches which opened the way into Brittany. The next day, XIX Corps succeeded in turning back the last German counterattacks against the American advance. Pressing south, Bradley's men finally succeeded in escaping the bocage and began to drive the Germans before them.


As Allied troops were enjoying success, changes took place in command structure. With the activation of Lieutenant General George S. Patton's Third Army, Bradley ascended to take over the newly-formed 12th Army Group. Lieutenant General Courtney Hodges assumed command of First Army. Entering combat, Third Army poured into Brittany as the Germans attempted to regroup.

Though the German command saw no other sensible course than to withdraw behind the Seine, they were ordered to conduct a large counterattack at Mortain by Adolf Hitler. Dubbed Operation Luttich, the attack began on August 7 and was largely defeated within twenty-four hours (Map). Sweeping east, American troops captured Le Mans on August 8. With his position in Normandy collapsing rapidly, Kluge's Seventh and Fifth Panzer Armies risked being trapped near Falaise.

Beginning on August 14, Allied forces sought to close the "Falaise Pocket" and destroy the German Army in France. Though nearly 100,000 Germans escaped the pocket before it was closed on August 22, around 50,000 were captured and 10,000 killed. In addition, 344 tanks and armored vehicles, 2,447 trucks/vehicles, and 252 artillery pieces were captured or destroyed. Having won the Battle of Normandy, Allied forces advanced freely to the Seine River reaching it on August 25.


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Hickman, Kennedy. "World War II: Operation Cobra and Breakout from Normandy." ThoughtCo, Apr. 5, 2023, Hickman, Kennedy. (2023, April 5). World War II: Operation Cobra and Breakout from Normandy. Retrieved from Hickman, Kennedy. "World War II: Operation Cobra and Breakout from Normandy." ThoughtCo. (accessed June 9, 2023).