Normandy was a battle of attrition for the British and Canadian troops, drawing in most of the available German reinforcements, especially armoured divisions, around Caen at the eastern end of the lodgement. These operations left the Germans unable to prevent the American breakout at the western end of the Normandy beachhead in early August 1944. Following the German attack towards Mortain, the American breakout and an advance by the 21st Army Group the German armed forces in Normandy were nearly enveloped in the Falaise pocket, and subsequently routed, retreating towards the Low Countries.