By July 1944, the Allies were in trouble. Since D-Day, they had advanced barely 30 kilometers—about 20 miles—in three weeks. What many had hoped would be a swift breakout from Normandy had turned into one of the most savage attritional battles of the Second World War. In the deadly maze of hedgerows, even the next village felt far away—Berlin might as well have been on another planet.

And yet, just one month later, everything changed. The Allies punched through the German lines and encircled much of their enemy in a huge cauldron known as the Falaise Pocket. It was a brutal, decisive finale to the Normandy campaign. How did they get stuck in the first place? What triggered the breakthrough? And did they miss a chance to win an even greater victory than the one they achieved?

Six days after D-Day, the Allied forces finally linked their beaches by capturing Carentan. As they pushed forward, a seven-mile gap opened in the German line. The next day, British tanks surged forward to exploit the opportunity. But as they advanced along a narrow road, a single German Tiger tank suddenly appeared. Its commander, Michael Wittmann, destroyed ten tanks and eighteen personnel carriers in just a few minutes. In part because of his actions, the British attack soon ground to a halt. The Allies’ best opportunity for an early breakout from Normandy vanished.

For Bernard Montgomery, the overall ground forces commander, this was serious. He had promised his colleagues at SHAEF that the Normandy campaign would take about three months. By that time, he expected the German forces to withdraw to defensive positions along the Seine. To stay on schedule, he had to capture two key objectives. In the west, American forces aimed to cut off the Cotentin Peninsula and seize Cherbourg, the only major deep-water port in the area. But their sector was dominated by the bocage—dense, hedgerow-lined fields that heavily favored defenders. In the east, British and Canadian forces targeted Caen, a vital road and rail hub originally meant to be captured on D-Day itself. Unlike the American sector, the countryside around Caen was relatively open. That should have helped—but it also exposed attacking troops to German fire.

Britain also faced a manpower problem. By 1944, four years of fighting in the Mediterranean, East Asia, at sea, and in the air had bled British reserves dry. Fresh replacements for infantry in Normandy were limited. For political reasons and for morale at home, Britain needed to preserve enough strength to influence the eventual postwar settlement. Montgomery, conscious of this, leaned heavily into using tanks rather than infantry whenever possible. As his chief intelligence officer put it, “Let metal do it rather than flesh.”

The Sherman tank, widely used by British and American units alike, was typical of the Allied armored vehicles in Normandy. While reliable, it often needed multiple hits to stop a Tiger or Panther. The real issue was that tanks had to work closely with infantry to be effective. In the bocage—patchwork fields, sunken lanes, streams, and dense hedgerows—Allied tanks struggled. They became easy targets.

Wary of heavy casualties, Montgomery decided against a direct frontal assault on Caen. Instead, British and Canadian forces under General Miles Dempsey planned to envelop the city in Operation Epsom. But beginning on June 19th, a massive storm in the English Channel wrecked Mulberry harbors, battered ships, and delayed the operation. Resupply suffered, and by the time Dempsey finally launched the attack on June 26th, fresh German units had arrived from the Eastern Front. Rain turned the ground into a quagmire and limited Allied air support. After days of costly fighting, only modest gains were made.

Then, on June 29th, Dempsey had to brace for a German counterattack. Several Panzer divisions were thrown into the fight—but they were committed piecemeal, and as the weather improved, Allied air power returned. Aircraft, naval guns, and artillery combined to blunt the attack. By July 1st, the battle ended with no clear tactical winner. Operation Epsom had failed to seize Caen, but it had forced Rommel and von Rundstedt—commanders of Army Group B and OB West—to commit nearly all their available reserves just to hold the line.

That fact shook German leadership. In a tense meeting with Hitler, both men explained the situation: either the German army withdrew to more defensible positions, or it risked destruction. Hitler refused. He ordered that there be no retreat. “We must not allow mobile warfare to develop since the enemy surpasses us in mobility,” he said. “Everything depends upon us confining him to his bridgehead and then fighting a war of attrition to wear him down and force him back.”

The war of attrition began in earnest. A symbol of that grinding combat was the Nebelwerfer—a multi-barreled rocket launcher whose distinctive howling sound terrified Allied troops. In the first seven weeks of the Normandy campaign, roughly 70% of British and Canadian casualties were inflicted by German mortars and Nebelwerfers. The troops gave them nicknames: “Moaning Minnies” and “Screaming Meemies.”

While Dempsey’s attacks ground to a stalemate in the east, American forces under General Omar Bradley were making better progress in the west. On June 18th, they cut the Cotentin peninsula and isolated Cherbourg. With limited German forces remaining in front of them, U.S. troops began storming the port on June 22nd. House-to-house fighting was intense, but artillery and support from Allied warships tipped the balance. Cherbourg fell by June 27th.

The victory was tempered by the state of the harbor. German engineers had carried out what one American called “the best-planned demolition job in history.” Docks, cranes, and facilities were shattered. It would be weeks before Cherbourg could handle meaningful volumes of supplies.

As June drew to a close, it became obvious the Normandy campaign was not going as expected. With the exception of Cherbourg, Allied lines had barely advanced beyond their mid-June positions. Bad weather, difficult terrain, and unexpectedly stiff German resistance were all contributing factors. Although Montgomery now had more than a million troops and 170,000 vehicles in the theater, he lacked enough open space to use his mobility advantage. Allied patience—especially at SHAEF—was wearing thin. Criticism of Montgomery grew.

Montgomery, however, remained confident. Thanks to Ultra decrypts, he knew that German forces were taking heavy losses and had few replacements. Hitler’s “no retreat” orders had locked the Germans into a battle of attrition they were bound to lose. Montgomery decided to exploit that. He would use the British Second Army as a magnet to hold German armored divisions near Caen, thereby allowing the American First Army to break out in the west where armor was thinner.

In early July, Rundstedt was replaced as German theater commander by Günther von Kluge after reportedly telling Hitler that the war was lost. It wasn’t far from the truth. In the east, Operation Bagration was annihilating German Army Group Centre. Meanwhile, Germany’s so-called V-1 “flying bombs” were raining on London, causing terror but failing to alter the strategic situation. Shortly after taking over, von Kluge also had to assume Rommel’s duties after the field marshal was badly injured in a strafing attack. At first, von Kluge held on to some optimism; he soon arrived at the same grim conclusion as von Rundstedt. Nonetheless, he obeyed Hitler’s orders and fought on.

After failing to envelop Caen, Montgomery decided a frontal assault was now unavoidable. This was the fight he had hoped to avoid. Dempsey’s Operation Charnwood opened with a heavy RAF bombing raid that reduced much of Caen to rubble. The bombing killed many civilians but did little to destroy the deeply entrenched defenders. On July 8th, British and Canadian troops attacked into a landscape of ruins. The Germans, exhausted but determined, fought stubbornly. By the evening of the 9th, the Allies had taken the northern half of Caen—but the rubble and casualties prevented any rapid exploitation.

Further west, Bradley’s forces now turned their focus on Saint-Lô, a key road junction. Advancing through the worst of the hedgerows, their progress was agonizingly slow. Glover Johns of the 29th Infantry Division described the grind: “Thus goes the battle—a rush, a pause, some creeping, a few isolated shots, some artillery fire, some mortars, some smoke, more creeping, another pause, dead silence, more firing, a great concentration of fire followed by a concerted rush. Then the whole process starts over again.” It took two weeks just to reach the outskirts. Saint-Lô fell on July 18th, by which time 95% of the city lay in ruins.

That same day, Dempsey launched Operation Goodwood, his largest armored attack to date. Over 2,000 aircraft—heavy bombers as well as tactical air—preceded the assault with another massive bombardment. British and Canadian armor initially surged forward. But the German defenses were deeply layered. Anti-tank guns, dug-in tanks, and well-sited infantry slowed the advance. By July 20th, Goodwood had run out of steam. The Allies suffered over 400 tank losses in a single day. SHAEF’s reaction was fury and alarm. Yet again, Montgomery saw the strategic picture differently. Seven German panzer divisions—over 600 tanks—had been pinned down facing Dempsey’s men. Only two panzer divisions with fewer than 200 tanks now opposed the Americans.

Bradley was ready to take advantage. Operation Cobra, the American breakout, opened with a devastating carpet bombing: about 1,500 B-17s and B-24s dropped roughly 3,300 tons of bombs in an hour on German positions west of Saint-Lô. The bombing shattered defenses and killed many German infantry. Some bombs fell short, killing about 100 American soldiers and wounding 500 more. Nevertheless, Cobra achieved its purpose. With many defenders destroyed or stunned, U.S. units punched through.

Seven weeks after D-Day, many Allied soldiers were now hardened veterans. Units had learned from earlier mistakes. Innovation helped too. One lieutenant and a sergeant showed that steel obstacles taken from the beaches could be welded onto the front of Shermans to form makeshift hedgerow cutters. Tanks equipped with these “Rhino” devices could break through bocage banks instead of exposing their bellies by climbing over them. Once the first line was breached, German defenses west of Saint-Lô, which were relatively shallow, crumbled quickly. Reserves that might have contained Cobra had already been drawn east to fight around Caen.

U.S. forces quickly captured Coutances on July 28th, then Avranches a few days later. The slogging bocage battle was over. Maneuver warfare returned to Normandy. Patton’s newly activated Third Army raced into Brittany, while Dempsey’s Second Army and Crerar’s First Canadian Army launched Operation Bluecoat to hold German units in place further east.

The German situation was rapidly becoming untenable, though Hitler refused to recognize it. In fact, he chose this moment to launch a counterstroke. He ordered von Kluge to mount a major armored offensive from around Mortain toward Avranches, intending to cut off Patton and potentially collapse the Allied front. Few German generals believed in the plan—especially with their forces under such pressure and Allied air power so strong. But after surviving an assassination attempt in July, Hitler’s control over the military was tighter than ever. His orders were carried out.

On the night of August 6th–7th, four panzer divisions attacked toward Mortain. In the initial darkness and heavy weather, they gained some ground. By morning, leading elements were close enough to threaten Avranches. But U.S. units defending the area fought with determination. A battalion surrounded on Hill 314 east of Mortain called down heavy artillery on German attackers at close range. RAF Typhoons also struck with rocket attacks. Though their accuracy varied, the psychological impact on German troops was significant. By the evening of August 7th, von Kluge learned that fewer than half of the attacking tanks were still operational. The attack had stalled.

Hitler, however, ordered that the Mortain offensive be “prosecuted daringly and recklessly to the sea… regardless of the risk.” In effect, German units were being ordered to drive deeper into a trap.

By August 8th, Patton had taken Le Mans and was driving north toward Alençon. Canadian forces were attacking south toward Falaise. The jaws of a massive encirclement were closing. On August 15th, the Allies landed in southern France under Operation Dragoon. Hitler later called this one of the worst days of his life. He dismissed von Kluge and ordered a general withdrawal from Normandy. It was far too late.

For the encirclement to succeed fully, the Allies needed to seal the Falaise Pocket swiftly. This is where controversy persists: Argentan. Patton’s forces had advanced quickly toward the town, but his line was stretched thin. Montgomery believed the Canadians, advancing through Falaise, would reach Argentan first and preferred the town to fall in their sector. When the Canadians became bogged down and Patton requested permission to push further, he was denied. For several days, a roughly 10-mile gap remained between the American spearheads near Argentan and the Canadian-Polish spearheads near Falaise. Through that gap, tens of thousands of German troops escaped.

Eventually, on August 19th, American and Polish units linked up near Chambois, finally closing the pocket. The Poles, in particular, fought a ferocious battle to hold Mont Ormel Ridge (Hill 262), a key position overlooking the last German escape routes. From that ridge, they could see the valley below teeming with retreating German columns. When the morning fog lifted, they called artillery down on the crowded roads. German units mounted desperate attacks to dislodge them, and the Poles suffered heavy casualties. Rain later grounded Allied aircraft, denying them the chance to further pulverize the trapped forces from the air. The Poles held until Canadian troops relieved them on August 21st.

By then, about 50,000 Germans had escaped eastward—but another 60,000 had been killed or captured inside the pocket. Eisenhower, visiting the area afterward, said that only Dante could describe what he saw. For hundreds of yards, he could walk on nothing but dead and decaying bodies.

On August 25th, Paris was liberated. By the end of the month, German forces had fallen back to the Seine, as Montgomery had originally forecast—three months after D-Day. Operation Overlord was officially over.

For the people of Normandy, liberation was both triumph and tragedy. Four years of Nazi occupation ended, but at a terrible cost: over 20,000 French civilians killed and hundreds of thousands left homeless. Historic towns like Caen, Saint-Lô, Le Havre, and Falaise lay in ruins. The Allies suffered a bit over 200,000 casualties in Normandy. The Germans lost close to 300,000 killed, wounded, or captured.

The Normandy campaign was not the lightning victory the Allies had hoped for. The fighting, especially in the bocage and around Caen, produced casualty rates reminiscent of World War I. But the Germans also suffered terribly—particularly in the Falaise Pocket and under relentless bombing and artillery fire. Combined with Soviet offensives like Operation Bagration in the east, the destruction of German forces in Normandy dealt the Wehrmacht a blow it could not recover from.

Even so, the advance into Germany would prove difficult. The Allied pursuit soon slowed, hampered partly by logistics. Without a major functioning port like Antwerp in their hands until late in the year, the Allies had to funnel most supplies over the Normandy beaches and through Cherbourg. Germany had suffered a decisive defeat in France, but the war was far from over.