Queen Guinevere
Merlin says that he can change that when he becomes king and assures him that Gwen will wait for him if she feels the same way. Arthur and Guinevere's relationship develops slowly over the course of the seasons, positives as well as negatives, but namely the two remain steadfast in their love for each other.
Gwen and Arthur marry, despite Uther's and Morgana's attempts to keep them apart. Following Arthur's death, Gwen becomes the queen regnant of Camelot.
Freya was a Druid girl who fell in love with Merlin, who she met when he helped her to escape from the bounty hunter Halig. She later died on the shores of the Lake of Avalon, after which she became the Lady of the Lake.
However, they soon found themselves running in the same circles the closer they got to Merlin. Eventually, Arthur and Gwen fell in love as the prince began to trust and rely on her counsel. But like every other couple, they had their ups-and-downs.
Gwen worked as Morgana's maid for many years before marrying Arthur, and inherited the throne after his demise. It is assumed that Gwen ruled Camelot as Queen Regnant until the day she died.
She was devoted to Lancelot (her lover) and her betrayal of her husband created the end of King Arthur's roundtable and the downfall of Camelot. Thomas Malory described Guinevere as 'a true lover' and believed she had a 'good end.
Here, Merlin survives the reign of Arthur, about the fall of whom he is told by Taliesin. Merlin spends a part of his life as a madman in the woods and marries a woman named Guendoloena (a character inspired by the male Gwenddoleu ap Ceidio).
Then Arthur is pulling him around and clasping the back of his head, tenderly, as though Merlin's the most precious thing in the world. 'Don't you dare ever lie to me again,' he says, and then kisses him. 'True love,' Merlin says breathlessly, when they break for air.
Morgana Pendragon, 607 - 621
Morgana married Merlin. Merlin was born in 603. They had one son: Arian Pendragon. Morgana passed away in 621, at age 14.
In short, only Arthur and Gwen's love / relationship can be definitively confirmed as romantic by canon. Canon also shows that Merlin and Arthur love and care deeply for one another, without confirming that love as romantic.
Merlin's purpose in life is to support and protect Arthur because he believes that Arthur will one day be the greatest of all kings and will restore peace to the region.
Eliza. At some point in his past Arthur met a young waitress named Eliza, whom he got pregnant with their son, Isaac. It is uncertain what relationship the two had but it can be deduced that they were on good terms.
Mary eventually marries a man named Barry Linton, but he dies leaving her a poor widow. Though Mary and Arthur cross paths again later in life, they never rekindle their romance again.
As of Chapter 212 of the novel, Arthur has finally returned his feelings to Tessia, believing that he had always had these feelings for her but was only trying to force them down. They have now made a promise to survive the war and start a relationship and family.
Though their courtship was complicated by their differing social classes (and later by interference from Morgana), they were ultimately married in the final episode of series 4. As of Arthur's death in the series finale, Gwen is now his widow and rules Camelot in his stead.
At first it seemed that Morgana had a crush on Arthur and she was always near him and supporting him, Arthur had feelings for her too and he thought that she was beautiful, time after she find out that she was the half sister of Arthur and Arthur was in love with Gwen.
Nimue and Merlin have a very different relationship in the legend. When Nimue and Merlin meet in the fifth episode, she asks the wizard why her mother instructed her to bring him the sword. By the end, viewers learn that not only did he and her mother have a relationship, but Nimue is actually Merlin's daughter.
Though one of the Welsh Triads (Triad 56) speaks of Arthur's three great queens (all named Gwenhwyfar), later romance generally gives him only one wife named Guinevere.
King Arthur of England and his queen, Silvia, have a son named Samson and a daughter named Grega. Unlike her brother, Grega is mentioned only once, when she's named in the introduction.
King Arthur marries Guinevere, daughter of the King of Scotland. Merlin tries to warn him against the marriage because Guinevere is in love with Sir Lancelot, one of Arthur's knights.
When Launcelot hears of the death of Arthur and Gawain, he comes to England in haste. He looks for the queen and finds her in a nunnery. For love of Guinevere as much as for remorse he takes on the habit of a priest. Guided by visions, he goes to Almesbury, where he finds Guinevere dead.
Guinevere hides in a nunnery, but her fate depends on the story. In some, Lancelot is killed in battle and she dies alone, Camelot in ruins around her. In other stories, the lovers reunite and live happily together in hiding.
Lancelot is also the lover of King Arthur's queen, Guinevere. Lancelot, also spelled Launcelot, also called Lancelot of the Lake, French Lancelot du Lac, one of the greatest knights in Arthurian romance; he was the lover of Arthur's queen, Guinevere, and was the father of the pure knight Sir Galahad.