Isolde

Isolde was a smuggler and the beloved of Tristan, who met up with Arthur and Merlin, when they were fleeing from Morgana. She helped Arthur rescue Camelot from Morgana, and died to protect him from Morgana's most deadly warrior, Helios.

Biography
At some point in the past, Isolde met Tristan and formed a smuggling partnership with him. The two travelled with precious goods and sold them illegally. During their time together, Tristan and Isolde fell in love and became "partners for life", though it is unknown if they were married or not.

Isolde was on another smuggling trip with a cargo of frankincense when she caught Arthur and Merlin who were fleeing Camelot and en route to Ealdor. Merlin convinced Tristan and Isolde not to kill them, and when offered gold, they agreed to let them travel alongside their party.

However, Agravaine's men caught up with Arthur and Merlin and Isolde was injured in a battle with one of the soldiers, only to be saved by Arthur. Isolde was grateful for this and therefore Tristan agreed to accompany Merlin and Arthur to Ealdor where Isolde could recover.

Merlin tended to Isolde, but when Agravaine tracked down and raided the village, they were forced to flee once again. She, along with the others, managed to escape into the caves and went with Arthur and Merlin afterwards to the forests. Almost fully recovered, Isolde stayed to help and also told Gwen not to give up on her relationship with Arthur.

Isolde and Tristan, having changed their opinion on Arthur and accepted him as a good man and just king, agreed to join him in the fight to retake Camelot. Isolde, Percival and Tristan led one of the attacks and Isolde later joined with Arthur, Gwen and Merlin in their push to the throne room to challange Morgana. Once it was clear that Morgana's magic was failing her and Helios began the attack on Arthur's group, Isolde joined the others in the fight with his men, taking down several of them. When Arthur was bested by Helios and about to be killed, Isolde ran Helios through while his back was turned but was fatally stabbed herself in the process.

Isolde died in Tristan's arms, apologising for leaving him and lamenting the future they would not have. Gwen and Merlin arrived just in time to see her final moments, speaking her last words, "hold me", to Tristan. Tristan's grief at losing his beloved helped push Arthur to restart his relationship with Guinevere (The Sword in the Stone).

Personality
Isolde was as fearless as any man and a skilled warrior. Her bravery and thirst for adventure made her a talented smuggler. Despite being a criminal, she was a kind hearted woman, comforting Guinevere about her ruined relationship with Arthur and telling her not to lose hope and saying that love is stronger than you could possibly imagine. She helped to control Tristan's more aggressive personality and although she loved him deeply, she was never afraid to tell him her true thoughts and feelings. Isolde was very loyal to people she trusted, being Tristan's partner for life (although it is unknown if they are married) and one of Arthur Pendragon's most loyal allies in the battle to save Camelot. She eventually gave her life to save Arthur from Helios.

Abilities
Isolde was a very talented swordswoman and during the battle of Camelot, she killed many warriors. Isolde fought extremely well alongside her lover, Tristan, and by working together they were a formidable team. King Arthur respected Isolde's fighting prowess enough to choose her and Tristan to confront Morgana and Helios, who were probably the most deadly warriors out of all of their enemies, instead of choosing the most skilled knights of Camelot.

Despite her skill, Isolde was far from unbeatable and was injured during a skirmish with Agravaine's warriors. Also, although she slew Helios, Morgana's most deadly warrior, she only did so by stabbing him from behind and even as he was dying, Helios managed to inflict a fatal counterstrike on Isolde.

Appearances

 * Series 4
 * The Sword in the Stone: Part One 
 * The Sword in the Stone: Part Two