D-Day occurred on June 6, 1944, when Allied forces launched major attacks on five beaches along the coast of Normandy, France. The attacks involved over 425,000 soldiers from countries like the U.S., Britain, and Canada who stormed the beaches and engaged in intense fighting with German forces. It was one of the largest amphibious military assaults in history and marked a turning point in World War 2 by undermining Germany's control of Western Europe. While the invasion was a military success that contributed to Germany's defeat within a year, it came at a massive human cost with over 425,000 casualties during the Normandy campaign.