|I do love a Spitfire (second only to P51 - Mustangs)|
The backstory isn't really told too much. Nearly half a million British and French troops were pinned down on the beaches in France and Belgium where the German Nazis could easily kill them. Why they didn't is a subject of great debate.
In order to save as many as possible, a flotilla of British private boats sailed to save as many men as possible.
For the "Christopher Nolan" edge (he did Momento and Inception) the timeline of the beach, boats and planes are all different (1 week, 1 day and 1 hour respectively) but integrate beautifully.
Ed captured it perfectly. It is the story of the British in general. Lots of people, lots of actors you know. BUT it was also the story of one young soldier (below) "Tommy" - just trying to stay alive. Played fantastically by unknown Fionn Whitehead.
When I interview for a job, I say my greatest skill - as a product manager - is to look at the details and quickly grasp what is the big picture, but still be able to focus on the one or two details that are critical for success. That is what Christopher Nolan has done with this picture.
The music is stunning.
In a lot of ways, this is reminiscent of a silent movie. Not that there isn't talking (you don't bring Mark Rylane, Kenneth Brannagh, Cillian Murphy and Tom Hardy and not loet them talk), but the action and music and the faces sell this story.