,
Gaius,
Morgana,
Merlin,
Arthur,
Uther and the
Great Dragon in the background •
Colin Morgan as
Merlin, Arthur's servant and Gaius' ward, who secretly develops his magical gifts under the gaze of kings Uther and Arthur, both of whom despise the art. Only Gaius and Lancelot are aware of his magic. Merlin also has an alter-ego, "Dragoon the Great" (conjured when Merlin performs an aging spell upon himself), who is considered a criminal by Uther and Arthur, and inspires profound fear in Morgana who recognises him as Emrys, her prophetic nemesis. Despite keeping his capabilities under wraps for years, by the end of the show, more people become aware of Merlin's powers, including Mordred, Agravaine, Morgana, Gwen, and Arthur. •
Bradley James as
Arthur Pendragon, the Prince and later King of Camelot, and the commander of the kingdom's knights. Despite being charged with carrying out his father's harsh edicts, Arthur is portrayed as a far more compassionate man, who defends the falsely accused before the king, and occasionally defies him. Arthur welcomes commoners Lancelot, Gwaine, Elyan, Mordred, and Percival as knights, and falls in love with Gwen, a serving girl, whom he later marries and makes Queen. He comes to regard his servant Merlin as a close friend and confidant, never realising how many times Merlin has had to save his life using magic. Arthur initially promises to lift Uther's ban on magic when he becomes king, but changes his mind when he thinks magic killed his father. Arthur is prophesied as "The Once and Future King", which means, even though he is killed in the final episode, Arthur Pendragon will rise again. •
Angel Coulby as
Guinevere ("Gwen"), Morgana's servant who later becomes Queen of Camelot. Gwen is spirited and brave which leads to an attraction between her and Arthur. Their relationship at first causes conflict within the kingdom, as Uther considers her unworthy due to her low status and forbids Arthur to court her, even accusing her of witchcraft when Arthur's affections for her do not diminish. However, Gwen proves popular among the common people, and strives to make Arthur and his advisers approachable to them. •
Katie McGrath as
Morgana Pendragon, Uther's ward who is later revealed to be his illegitimate daughter. Initially a kind and empathetic young woman, Morgana comes to despise Uther for his prejudice against magic and when she realizes he would never accept her if he knew of her magical powers, she begins covertly plotting against him. She becomes the show's primary villain by the third series, coveting Arthur's throne. •
Anthony Head as
Uther Pendragon (series 1-4; guest series 5), Camelot's stubborn king, who shows Arthur repeated tough love and ruthlessly enforces the kingdom's strict ban on sorcery. Although meaning well, Uther earns himself many enemies in his brutal fight against magic. He is devoted to Morgana and her ultimate betrayal leaves him a broken man. •
Richard Wilson as
Gaius, the court physician and Merlin's surrogate father and mentor. Once a sorcerer himself, Gaius abandoned the practice but occasionally practises it when Merlin needs help. A wise man with a long memory, Gaius is one of Uther's closest advisers, and always among the first to realise what is really happening when magic threatens the kingdom. •
Nathaniel Parker as
Agravaine de Bois (series 4), Arthur's uncle who arrives in Camelot to assist him after Uther's breakdown. Initially a trusted adviser to Arthur, he is later identified as a traitor working with Morgana. Aggravaine blames Uther for the death of his sister, Arthur's mother, Queen Igraine. •
John Hurt as the voice of
the Great Dragon, also known as Kilgharrah, the last of his kind after Uther destroys all of his kin and makes an example of him by imprisoning him in a vast cave beneath the castle. The Great Dragon gives Merlin advice and forges the sword of
Excalibur in his breath for Arthur, but persistently demands his freedom in return. Merlin eventually releases him, unwittingly unleashing a full-on assault on Camelot by the dragon, seeking revenge for his murdered kin. However, Merlin learns from his father that he is descended from a long line of dragonlords, and is able to use that power to control the Great Dragon. Subsequently, Merlin and the dragon become close friends with the dragon often helping Merlin when needed. == Episodes ==