Director Sam Mendes is adding major stars to his upcoming World War I drama "1917."

Benedict Cumberbatch, Colin Firth, Mark Strong, and Richard Madden have joined the film. The cast already includes George MacKay and Dean-Charles Chapman.

The movie follows young British soldiers on a single day at the height of World War I.

This is Mendes’ first feature film since his Bond outings "Skyfall" and "Spectre." He has passed 007 directing duties on to Cary Fukunaga.

Cumberbatch can next be seen in "Avengers: Endgame." Firth most recently appeared in "Mary Poppins Returns." Strong is next in "Shazam!" And "Game of Thrones" alum Madden recently received acclaim for the series "The Bodyguard."

Filming is set to begin April 1 and the release date has been set for December 25.