On 26 May 1940, an operation began which would, to a large part, determine the outcome of the War. Following the disastrous Battle of France, the bulk of the British army was stranded in the north of the country, and the only means of continuing was to somehow retreat across the Channel, back to the homeland. Whether they could do this without heavy losses was far from certain.
The subject was tackled once before, back in 1958, but now Christopher Nolan - of The Dark Knight trilogy, Inception and Interstellar fame - is taking it on, and the first teaser trailer is here.
It's short, tense and it's certainly already got us excited about the movie, which stars Tom Hardy, Mark Rylance, newcomer Fionn Whitehead and even One Direction's Harry Styles, who has taken his first film role (although sadly he's not in this clip, which has left large sections of the internet very disappointed indeed).
Take a look and see what you think.
Dunkirk is in cinemas 21 July 2017