Game of Thrones star and Other Voices host Aidan Gillen has been cast opposite Charlie Hunnam, Jude Law, Eric Bana, Astrid Bergès-Frisbey and Djimon Hounsou in director Guy Ritchie's King Arthur.
Hunnam is in the title role, with Gillen as Goosefat Bill, Bergès-Frisbey as Guinevere, Hounsou as Bedivere, Law as Vortigern and Bana as King Uther Pendragon.
Filming has begun at Warner Bros Studios in Leavesden in the UK, with location shooting to take place in Wales and Scotland.
The film is due for release on July 22, 2016.
Studio Warner Bros says: "The bold new story introduces a streetwise young Arthur who runs the back alleys of Londonium with his gang, unaware of the life he was born for until he grasps hold of the sword Excalibur - and with it, his future. Instantly challenged by the power of Excalibur, Arthur is forced to make some hard choices."
It continues: "Throwing in with the Resistance and a mysterious young woman named Guinevere, he must learn to master the sword, face down his demons and unite the people to defeat the tyrant Vortigern, who stole his crown and murdered his parents, and become King."