Decision to Invade. The decision to invade France came only after long discussion and argument. Stalin had long insisted that the Western allies open a "second front" on the European continent to take pressure off Soviet troops, who were doing the bulk of the fighting against the Germans. The Americans also felt that a direct strike in the heart of Europe was the best way to secure a quick victory, although they were not prepared to move as quickly as Stalin demanded, in part because of shortages of landing craft.American troops hit the beaches at Normandy.
The British favored a plan of slow encirclement, beginning with an attack in the Balkans. Victory would come less quickly than with a direct strike, Churchill conceded, but he felt that that was a worthwhile trade-off in order to forestall Soviet domination in the Balkans after the war. In the end, however, the American and Soviet view prevailed.
The final plan for the invasion of France, called by the code name Operation Overlord, provided the most complete welding in history of the forces of two powerful allies. General Eisenhower was designated supreme Allied commander in chief, with Air Chief Marshal Sir Arthur Tedder of the RAF as deputy commander. Sea and air commands also went to British officers, Admiral Sir Bertram Ramsay and Air Chief Marshal Sir Trafford Leigh-Mallory. General Carl A. Spaatz commanded United States strategic air forces in Europe. Montgomery at first was Allied commander in chief on land; later he commanded a British group of armies while Bradley commanded an American group.
Previous Experience. Before World War II there had been few examples in military history of successful amphibious operationsthat is, joint army and navy attacks against a hostile coast. The British failure at Gallipoli in World War I was fresh in memory. Now the role of air power had to be considered also.
The Germans in Norway and the Japanese in the Pacific were the first to combine land, air, and naval forces successfully, but they landed at undefended or weakly defended points. The British experimented with amphibious raiders called commandos and the United States organized a similar force called Rangers. But a large-scale commando raid on the coast of France at Dieppe in August, 1942, resulted in heavy losses and much discouragement.
Meanwhile, the U.S. Marines, who devised methods of amphibious warfare as early as 1934, were perfecting landing techniques in the Pacific. Then the British and American armies gained experience in successful landings in North Africa, Sicily, and Italy. Lessons were learned from these landings, and when the time came for Operation Overlord the Allies were well prepared for the largest amphibious invasion in history.
Four thousand ships moved Allied troops across the English Channel to the beaches of Normandy on June 6, 1944, D-Day (invasion day). A gigantic gun and rocket bombardment from Allied warships softened up resistance in the landing areas, while planes swept the skies clear of German defenders and attacked German troops on the ground. Paratroops and glider-borne troops had landed in the rear the night before the invasion, disrupting German defenses and capturing strategic locations.
The invasion came as a surprise to the Germans. They had expected a landing at Calais and were convinced that the Normandy landings were merely a diversion to pull defenders away from the site of the real invasion, which would occur later. By the time Hitler committed his heavy panzer units, a firm beachhead had already been established. Nonetheless, there was heavy fighting before the beaches were secured, particularly at Omaha Beach in the American sector. (The beaches attacked by American troops were code-named Omaha and Utah, and those attacked by British and Canadian troops were called Gold, Juno, and Sword.)
The British troops struck out toward Caen, while the American First Army moved to capture the port of Cherbourg. Cherbourg's port facilities were needed to handle the enormous shipments of supplies required to keep the troops on the offensive. To unload ships until the port could be taken, breakwaters were constructed off the invasion beaches by sinking old ships and huge prefabricated caissons to form artificial harbors, which were code-named Mulberries. Despite being damaged by a storm on June 19, these facilities were a great success.
The Allied offensive was slowed by the dense hedgerows of the French countryside. which provided excellent defensive positions for the German troops. After heavy fighting and great losses, Cherbourg was taken on June 27. Strong German resistance held the British outside Caen until July 9. Meanwhile the Americans probed southward, seeking a break in the German lines.