Friday, June 6, marks 81 years since the allied forces of World War II stormed the beaches of Normandy, France on D-Day. The amphibious assault – codenamed Operation Overlord – involved landing more than 155,000 Allied soldiers on the French beaches, resulting in 4,427 casualties – according to the National D-Day Memorial Foundation.

Day, the first day of the Normandy landings that laid the foundations for the Allied defeat of Nazi Germany in World War II.