D-Day was the code word designating June 6, 1944, the day for the invasion of the Cotentin Peninsula in Nazi-occupied Normandy by Allied forces during the Second World War. The invasion was the largest amphibious landing in history. Within one week of D-Day, the Allies had landed, in the face of hostile obstacles, 326,000 men, 50,000 vehicles, and over 100,000 tons of supplies—a technical miracle.
The landing established a firm beachhead in Normandy from which the Allied armies swept across France, liberating Paris on August 25, 1944. Ultimately, armies of the Western Allies linked up with the Red Army on the Elbe River on April 25, 1945, for the final defeat of Germany ~ from The reader's companion to American history, D-day.
"Landing on the coast of France under heavy Nazi machine gun fire are these American soldiers, shown just as they left the ramp of a Coast Guard landing boat." Photograph by CphoM. Robert F. Sargent, June 6, 1944 from the National Archives and Records Administration.