The invasion of Normandy cost the Allies more than 9,000 casualties of war, but won a battle so significant that it can be considered the war's primary turning point. More than half a million Allied troops occupied Normandy only a week after the invasion and marked a time when the Germans began retreating from the Allies instead of decimating them.

The Buildup

By 1944 the Allies had gained momentum: The Soviets had gained ground at Stalingrad, and North Africa had been liberated by the Americans. Stalin continued to call for an invasion of Europe; and after Roosevelt, Stalin and Churchill met in Tehran, Operation Overlord was finally designed. Allied troops would invade the coast of Northern France. The advance would force the Germans to fight a war on two fronts and would relieve some of the pressure on the Soviet troops, which was one of Stalin's primary concerns. The Germans knew it wouldn't be long before the Allies mounted an attack, and when the Allies learned that the Germans were anticipating an attack on Calais, they leaked false intelligence to reinforce that anticipation as a diversion.

Operation Overlord

Before the sun rose on June 6, 1944, American and British paratroopers landed in Normandy, attacked rear German troops, and disabled telephone lines while British glider units took control of several bridges. The Allies also sent coded messages through the BBC that alerted the French Underground to sabotage additional German communication lines. Meanwhile, more than 2,000 British and American ships waited off the coast. At sunrise, bombers attacked German targets. By this time the Germans had detected the fleet on radar, and when they opened fire, the naval forces returned that fire. By 8:30 a.m., Allied troops had landed on all targeted beaches, and by 1:00 p.m., full reinforcements had arrived, and the Allies had secured the beaches at Normandy. By dusk, more than 150,000 Allied soldiers had landed at Normandy.

Hitler's Response

One of the key factors to the Allies being able to take Normandy was the time afforded by Hitler's indecision. When German forces first notified Hitler of the attack, he was concerned it might be a diversion from the attack on Calais that he expected, and he declined to release additional troops and artillery to aid in their defense. Additionally, German Field Marshall Rommel, who was in charge of coastal forces, was away from his troops and had to travel nearly 400 miles by car to reach them. The German field commanders were on their own. By four in the afternoon, when Hitler was finally convinced that Normandy wasn't a diversion and gave the order for a full attack, the Allies had already won the coast.

The Aftermath

The victory at Normandy marked an access point to Europe for Allied troops, and shortly after D-Day, the Allies took the port at Cherborg -- and 25,000 German prisoners of war -- under the charge of General Omar Bradley. German Field Marshals -- including Rommel -- tried to persuade Hitler to admit defeat and end the war, but Hitler remained obstinate. The Allies took another 50,000 prisoners at Falaise. In August of that year, the Allies liberated Paris. In early 1945, the Allies defeated the Germans at The Battle of the Bulge. In April, Hitler committed suicide, and on May 7th, the Germans surrendered to General Dwight D. Eisenhower.