<human>:  I have a question about a book I’m reading called D-Day: 50 Years On. Where was D-Day?
<bot>: D-Day was the code name for the Allied invasion of Normandy on June 6, 1944. The Allied invasion of Normandy was the largest seaborne invasion in history, with more than 150,000 troops landing on the beaches of Normandy, France. The invasion was part of Operation Overlord, the largest amphibious invasion in history.