Breakout to the East
When the Third Army became operational on August 1, General Patton took control not only of the 8th Corps operations in Brittany but also of Maj. Gen. (later Gen.) Wade H. Haislip’s 15th Corps, which turned southeastward toward Mayenne. Taking Mayenne on August 4, capturing Laval on August 5, and seizing Le Mans on August 8, the 15th Corps formed an enveloping pincer that extended more than 75 miles around the German left flank. Meanwhile, the First Army also swung southeastward toward the road centers of Vire and Mortain, thereby starting a swinging movement designed to carry the Allies to the Seine River and the periphery of the lodgment area envisioned by the Overlord planners. But the Germans turned and sprang. Hoping to regain Avranches and thereby to close the holethat Bradley had punched in their defenses, the Germans launched a counterattack at Mortain on August 7. They were motivated by the desire to reestablish the conditions of static warfare that had served them well during June and most of July. They struck the 30th Infantry Division of Collins’ 7th Corps with full force. Quickly reinforced by Bradley, the 7th Corps fought a magnificent defensive battle to halt the German threat.
By attacking westward through Mortain toward Avranches, the Germans had placed their heads into a potential noose. Bradley saw the possibility of encircling the Germans and proposed this maneuver to Montgomery, who agreed. Bradley therefore directed Patton to turn the 15th Corps northward from Le Mans toward the successive objectives of Alengon and Argentan with the purpose of cutting behind the Germans at Mortain. If Montgomery’s forces drove southward from the Caen area and reached Falaise, the Allies would form a pocket and threaten the enemy’s Fifth Panzer and Seventh armies with encirclement and annihilation. General Crerar’s Canadian First Army, which had become operational on the Continent on July 23, attacked southward toward Falaise on August 8, but gained little ground. In contrast, Haislip’s 15th Corps took Alengon and was within sight of Argentan by August 13. Because the American troops had reached the boundary line separating American and British zones of operations, Bradley ordered Patton to halt further advance by Haislip’s corps. This decision was dictated in part by the fact that Crerar was about to launch a heavy attack on the following day. On August 14, after 800 planes had dropped 3,700 tons of bombs to clear a path for the ground troops, the Canadians launched their attack. Two days later they reached Falaise. Allied forces were then only 15 miles apart, but the Germans were escaping eastward out of the pocket through this 15-mile sector, called the Argentan-Falaise gap.
Bradley had meanwhile approved Patton’s plan to send part of the 15th Corps to the Seine. This movement got under way on August 14. Five days later the 79th Division was crossing the Seine River and establishing a bridgehead on the east bank. Other troops of the 15th Corps, soon joined by the First Army’s 19th Corps under Corlett, were driving down the west bank of the Seine and pushing the Germans toward the mouth of the river, where escape crossings were harder to find. While this secpnd encirclement at the Seine was in progress, the Allied troops holding the shoulders of the first encirclement at Argentan and Falaise were at last making contact at Chambois and Trun. They thus closed the pocket on August 20, trapping more than 50,000 German troops, destroying an additional 10,000, and sending the Fifth Panzer and Seventh armies reeling eastward across the Seine in defeat. Field Marshal Walter Model meanwhile had become commander in chief in the west, replacing Kluge, who committed suicide.
By this time two more American corps had come on the scene. Maj. Gen. (later Gen.) Walton H. Walker’s 20th Corps, after taking Angers, turned to take Chartres. Maj. Gen. Gilbert R. Cook’s 12th Corps drove toward Orleans. By August 20, when the First and Third armies pulled up to the Seine, Eisenhower had already decided to ignore the original limits of the lodgment area and cross the river in strength in pursuit of the disorganized enemy force. Meanwhile, as British and Canadian armies moved to the Seine, American and French troops liberated Paris.