Director Christopher Nolan and actor Mark Rylance didn't know just how famous Harry Styles was before they started production on their upcoming film "Dunkirk." Nolan said, "The truth is, I cast Harry because he fit the part wonderfully and truly earned a seat at the table." The 23-year-old former 'One Direction' member plays a British soldier in Nolan's suspense-thriller about the evacuation of Allied soldiers from Dunkirk, France, in1940. Rylance, a lead actor in the film, said, "[My niece] was just more excited than anything I've ever done because I was going to be acting with Harry Styles. "Dunkirk" opens in North American theaters July 21st. It also features Kenneth Branagh, Cillian Murphy and Tom Hardy.