The Normandy Battlefields: D-Day & the Bridgehead ended as the Allies fought to expand their D-Day foothold. In Bocage and Breakout, Leo Marriott and Simon Forty take the story forward as the success of the invasion continued into the Cotentin, with Cherbourg falling on 29 June, before it bogged down in face of determined German defense and the bocage countryside—innumerable small fields surrounded by hedgerows, each one hiding anti-tank weapons, mortars and machine guns. As US First Army fought its way south, on the eastern edges of the bridgehead, British and Canadian forces were fighting a war of attrition around Caen facing the bulk of the German armor as division after division was fed into Normandy. Like a pressure cooker, the fighting intensified until, seven weeks after D-Day, Operation ‘Cobra' broke the German line. Quickly Patton's Third Army, operational from 1 August, flooded through the gap exploiting the German confusion, encircling what was left of the German armies in the Falaise Pocket and advancing quickly through into Brittany. Three weeks later, the Battle of Normandy was over, the routed German Army—without most of its heavy weapons left in the Falaise Pocket or on the banks of the Seine—was retreating helter skelter back towards Germany and the Low Countries pursued by the Allies in a reverse of the 1940 Blitzkrieg campaign.