D-Day

Beginning of the invasion of Normandy on June 6, 1944, during World War II. The term D-day remains standard military parlance for the first day of the military operation, as does H-hour for the time the operation begins. D-day began Operation Overlord, the long-anticipated invasion of the Atlantic coast of German-held Europe by the Allies. The decisive battle that followed lasted two months and ultimately decided the fate of Germany in the west.

With its entry into World War II, the United States brought a determination to land Allied armies in Western Europe and invade Germany by the most direct means possible. The British, having been ejected from France in 1940 and further routed from Greece and Libya in 1941, had less interest in fighting the German army on the old battlefields of World War I. [Page 179]They therefore sought alternative strategies based upon the Mediterranean theater of operations.

American troops in landing craft going ashore on one of four beaches in Normandy, France, during the D-day invasion of 1944. The D-day invasion, launched on June 6, 1944, was part of an all-out Allied assault on northern France. It marked the beginning of a sweep through Europe that would finally end with the defeat of Nazi Germany in the spring of 1945. The D-day invasion, which involved a flotilla of more than 10,000 ships, was the largest amphibious operation in history.

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Although the viability of the American invasion plans for 1942 and 1943 remains doubtful to this day, there was no denying that conditions were right in 1944 for a cross-channel attack. The German U-boat offensive had been defeated in the Battle of the Atlantic, sufficient landing ships and craft filled British ports, Allied air superiority was established, and sufficient troops had been ferried to Great Britain for the Normandy Invasion.

United States general Dwight D. Eisenhower, the Supreme Allied Commander in Europe, had directed a planning effort of more than two years for this invasion. Under it, Allies placed two field armies ashore at Normandy in a few days, using five invasion beaches, overwhelming naval and aerial bombardment, and key airborne attacks. The number of beach assaults was raised from three to five with the expectation that at least one would fail, but only the assault on the beach code-named Omaha proved to be a close event. A successful deception plan, using false units, radio traffic, and decoys, kept many German forces oriented to the Pas de Calais beaches until too late.

The defeat of weak German counterattacks against the landing area owed much to the successful air interdiction campaign, which made armored movement in daylight almost suicidal for the Germans. The decisive battle to break out of the beachhead required the efforts of two army groups and twice the time originally planned. The British and Canadians finally cleared Caen, and, after heavy combat, U.S. forces broke out at Saint-Lô. However, the extended campaign also produced the annihilation of the German Seventh Army and the decimation of most German army forces on or near the Normandy front.

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