Eisenhower led the largest invasion in history on June 6, 1944, known as D-Day, to liberate Western Europe from Nazi Germany. Over 3 million Allied troops attacked five beaches in Normandy, France against heavy German resistance. Despite facing fortified defenses and over 11,000 casualties on D-Day alone, the Allies established a foothold in Normandy and continued advancing, eventually liberating Paris two months later. Within six weeks, the Allies had suffered over 100,000 casualties but managed to free most of Western Europe from German control by September 1944, marking a turning point in the war.