UPDATED: One Direction singer Harry Styles and Fionn Whitehead will star in Christopher Nolan’s World War II action-thriller “Dunkirk.”

They join Tom Hardy, Mark Rylance and Kenneth Branagh in the film, which centers on the British military evacuation of the French city of Dunkirk in 1940. “Dunkirk” will mark their feature film debuts.

British actors Jack Lowden and Aneurin Barnard have also joined the cast of “Dunkirk.”

Variety reported exclusively in December that Nolan had come on to direct and produce the film with his longtime partner Emma Thomas. They have been conducting an extensive casting search.

“Dunkirk” will be shot on a combination of Imax 65mm and 65mm large format film. Shooting will begin in May at many of the locations where the true-life events actually took place.

A quickly-assembled British fleet of more than 800 boats saved more than 335,00 soldiers who had been cut off by the German Army. As the rescue was concluding, British Prime Minister Winston Churchill told Parliament, “We shall fight on beaches, we shall fight on the landing grounds, we shall fight in fields and in the streets, we shall fight in the hills. We shall never surrender.”

“Dunkirk” hits theaters on July 21, 2017.

Styles, 22, joined the group One Direction in 2010. The band, which has released five studio albums, was the subject of the 2013 Morgan Spurlock documentary “One Direction: This Is Us,” which grossed $68 million worldwide.

Newcomer Whitehead appeared in ITV’s three-part horror-drama “Him.” Lowden appeared in BBC-Weinstein Company’s ‘War and Peace” and Amma Asante’s “A United Kingdom.” Barnard portrayed King Richard in the BBC-Starz miniseries “The White Queen.”

The news about the offer to Styles was first reported by Deadline Hollywood.