From the director of Sherlock Holmes: A Game of Shadows, a hero named Arthur gains assist from the wizard, Merlim, a princess, Guinevere and an owl, Archimedes in a search to find the sword, known as Excalibur to defeat the evil King Kayg, who has overthrown his father, King Uther Pendragon.
- Arthur (Shia LaBeouf)
- Guinevere (Ashley Greene)
- Merlin (Christopher Lioyd)
- Uther Pendragon (Stephen Lang)
- Igraine (Cate Blanchett)
- Archimedes (John Hurt)
- King Kayg (Tom Hiddleston) - the main antagonist