The D-Day invasion, also known as Operation Overlord, took place on June 6, 1944, during World War II. It was a massive military operation where Allied forces, including troops from the United States, United Kingdom, and Canada, landed on the beaches of Normandy, France. The goal was to liberate Western Europe from Nazi occupation. The invasion involved extensive planning and coordination, with over 156,000 soldiers landing on five beach sectors: Utah, Omaha, Gold, Juno, and Sword. The successful landings marked a turning point in the war, leading to the eventual defeat of Nazi Germany and the liberation of Europe.