from u-s-history.com,

The Battle of Normandy was fought during World War II in the summer of 1944, between the Allied nations and German forces occupying Western Europe. More than 60 years later, the Normandy Invasion, or D-Day, remains the largest seaborne invasion in history, involving nearly three million troops crossing the English Channel from England to Normandy in occupied France.

Twelve Allied nations provided fighting units that participated in the invasion, including Australia, Canada, Belgium, France, Czechoslovakia, Greece, New Zealand, the Netherlands, Norway, Poland, the United Kingdom, and the United States.

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