| Character | Portrayed By | Description | | :--- | :--- | :--- | | | Jamie Campbell Bower | A young, headstrong, and somewhat naive peasant who is suddenly thrust into kingship. He must grow up fast and learn what it takes to lead. | | Merlin | Joseph Fiennes | A powerful and enigmatic sorcerer who serves as Arthur's advisor. He is a man with dark secrets, haunted by visions of a disastrous future. | | Morgan | Eva Green | Arthur's formidable half-sister. Intelligent, ambitious, and dangerously powerful, she will stop at nothing to seize the throne for herself. | | Guinevere | Tamsin Egerton | A beautiful and spirited noblewoman who becomes the love interest of Arthur. Her relationship with Arthur is central to the story's drama. | | Igraine | Claire Forlani | The mother of Morgan and Arthur, who is caught between her two children in their battle for power. |