Dunkirk: Christopher Nolan had no idea how famous Harry Styles was when he cast him

'The truth is, I cast Harry because he fit the part wonderfully and truly earned a seat at the table'

Anyone looking at Harry Styles' casting in Dunkirk may be led to believe it was all some kind of promotional stunt - get a winsome pop star to appear in your (admittedly slightly risky) British war epic, and rake in a guaranteed audience.

However, director Christopher Nolan doesn't seem to have quite grasped how famous Styles is when he cast him as one of the young soldiers trapped on the beaches of France during WWII's Operation Dynamo.

"I don't think I was that aware really of how famous Harry was" Nolan admitted to The Hollywood Reporter. "I mean, my daughter had talked about him. My kids talked about him, but I wasn't really that aware of it. So the truth is, I cast Harry because he fit the part wonderfully and truly earned a seat at the table."

The same goes for star Mark Rylance, who plays a fisherman who aids in the evacuation, having only learned of Styles' vast popularity through his 11-year-old niece.

"She was just more excited than anything I've ever done because I was going to be acting with Harry Styles," Rylance said, whose niece is clearly less interested in his Oscar and three Tonys. "I went up in her estimation. I won the Harry!"

Nolan's Dunkirk will follow individuals caught up in the Dunkirk evacuation of May and June 1940, in which 338,226 soldiers were rescued from the beaches of France after being surrounded by the German army.

Dunkirk hits UK cinemas 21 July.