The Falaise pocket or battle of the Falaise pocket (Kessel von Falaise; 12–21 August 1944) was the decisive engagement of the Battle of Normandy in the Second World War. Allied forces formed a pocket around Falaise, Calvados, in which German Army Group B, with the 7th Army and the Fifth Panzer Army (formerly Panzergruppe West) were encircled by the Western Allies. The battle resulted in the destruction of most of Army Group B west of the Seine, which opened the way to Paris and the Franco-German border. Six weeks after the 6 June 1944 Allied invasion of Normandy, German forces were in turmoil. The Allies had experienced strong resistance. British forces had expected to liberate Caen immediately after the invasion but this took nearly two months. Similarly, US forces had expected to control Saint-Lô by the 7 June, yet German resistance delayed this until after Caen's liberation. However, the German Army expended irreplaceable resources defending the frontline. Allied air forces achieved air superiority up to 100 km behind enemy lines. Allied forces continuously bombed and strafed German logistical lines, limiting the availability of fuel and ammunition. The German Army had used its available reserves (especially its armour reserves) to buttress the front lines around Caen, leaving few additional troops to create successive lines of defence. The Allied armies developed a multi-stage operation. It started with a British/Canadian attack along the eastern line around Caen in Operation Goodwood on 18 July. The German Army responded by sending a large portion of its armoured reserves to defend. On 25 July thousands of American bombers carpet bombed a 6,000-metre corridor on the western end of the German lines around Saint-Lô in Operation Cobra. American forces pushed into the resulting gap. The German forces were overwhelmed and the Americans broke through. On 1 August, Lieutenant General George S. Patton was named the commanding officer of the newly recommissioned US Third Army—which included large segments of the force that had broken through the German lines.