D-Day: The Invasion of Normandy When on D-Day-June 6, 1944-Allied armies landed in Normandy on the northwestern coast of France, possibly the one most critical event of World War II unfolded; for upon the outcome of the invasion hung If the invasion failed, the United States might turn its full attention to the enemy in the Pacific-Japan-leaving Britain alone, with most of its resources spent in mounting the invasion. That would enable Nazi Germany to muster all its strength against the Soviet Union. By the time American forces returned to Europe-if indeed, they ever returned-Germany might be master of the entire continent. Although fewer Allied ground troops went ashore on D-Day than on the first day of the earlier invasion of Sicily, the invasion of Normandy was in total history's greatest amphibious operation, involving on the first day 5,000 ships, the largest armada ever assembled; 11,000 aircraft (following months of preliminary bombardment); and approximately 154,000 British, Canadian and American soldiers, including 23,000 arriving by parachute and glider. The invasion also involved a long-range deception plan on a scale the world had never before seen and the clandestine operations of tens of thousands of Allied resistance fighters in Nazi-occupied countries of western Europe. American General Dwight D. Eisenhower was named supreme commander for the allies in Europe. British General, Sir Frederick Morgan, established a combined American-British headquarters known as COSSAC, for Chief of Staff to the Supreme Allied Commander. COSSAC developed a number of plans for the Allies, most notable was that of Operation Overlord, a full scale invasion of France across the English Channel. Eisenhower felt that COSSAC's plan was a sound operation. After reviewing the disastrous hit-and-run raid in 1942 in Dieppe, planners decided that the strength of German defenses required not a number of separate assaults by relatively small units ...
