Isolde

"Whatever happened to the idea of finding a bit of land and settling down?"

- Isolde to Tristan

Isolde was a smuggler and the beloved of Tristan. She met 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. Isolde was injured in the 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 Forest of Ascetir. 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 challenge 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. 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 fearless 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, 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
Although Isolde was a good fighter, who managed to kill her fair share of Morgana's knights, she was wounded during a skirmish with Agravaine's forces.

She slew Helios, Morgana's most deadly warrior, by stabbing him from behind and, 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 

In The Legend
Isolde (like her lover, Tristan) probably started off as part of an Irish legend completely separate from the Arthurian cycle, but (along with Tristan, who became known as a Knight of the Round Table as well as the nephew of Mark of Cornwall) later joined the classic cast of King Arthur stories.

Legend holds that she was an Irish princess who married King Mark of Cornwall. Her reasons for doing so are changed from story to story, but most often she is tricked or simply misunderstands what is happening and does not discover the truth until it is too late.

Knowing she does not love Mark, Isolde's mother the queen entrusts her daughter's maid Brangaine with a love potion that will make Isolde love whomever she drinks it with. By accident, Isolde and Tristan, Mark's nephew, drink it together and fall madly in love.

Together, Tristan and Isolde have an affair behind Mark's back not unlike the Lancelot/Guinevere/Arthur triangle.

In most stories, Tristan dies before Isolde (unlike in the Merlin series, where Isolde dies in Tristan's arms and there is no mention of his dying as well), and she dies weeping over his dead body or else goes on brokenly without him until death claims her. Apparently, their graves grew plants, sometimes an Irish Briar and Cornwall's Rose, that intertwined and always grew back no matter how many times it was cut, ensuring they would never again be separated by the morals of the world.

The lesser-known Isolde of the White Hands is a completely separate character from this Isolde, though they share a name.