What is D-Day? D-Day was the allied invasion of Normandy during World War II. Also known as the Normandy landings or Operation Neptune, this monumental event was the largest seaborne invasion in history. A pivotal moment in World War II, D-Day began shifting the balance of power in Western Europe away from Nazi Germany. Hey, we sell tours too! While the information provided here is free, … [Read more...] about What is D-Day? Normandy During WWII