Dunkirk is an original script by Nolan that is based upon the real life incident known as Operation Dynamo, which unfolded in May and June 1940, during the early days of World War II. Following the Battle of France, thousands of British, French, and Belgian soldiers were hopelessly surrounded by the German army at the beaches of Dunkirk, France. Almost inexplicably, the German forces decided to hold back; which set the stage for the emergency evacuation of over 300,000 troops. It quickly became known as “the Miracle of Dunkirk.”