Eric Bana has signed on to star in Warner Bros.' fantasy adventure Knights of the Round Table, playing Uther, the father of Charlie Hunnam's King Arthur. Astrid Berges-Frisbey is also set to star as Guinevere, with Jude Law in talks to play the villain and Djimon Hounsou in negotiations to play a character named Bedivere, who is described as a Merlin-eseque mentor to Arthur.Warner Bros.