BBC Merlin

Merlin is a British TV series based on the Arthurian Legends.

Plot
Merlin is a young and powerful warlock who arrives in the kingdom of Camelot after his mother arranges for him to stay with the court physician, Gaius. He discovers that the king, Uther Pendragon, outlawed magic twenty years earlier in an event known as the Great Purge and imprisoned the last Dragon deep under the kingdom. After hearing a mysterious voice inside his head, Merlin makes his way to the cavern beneath Camelot where the Great Dragon tells Merlin that he has an important destiny: to protect Uther's son, Arthur, who will return magic to Camelot and unite the land of Albion.

When Merlin meets Arthur, Merlin believes that he is an arrogant bully and Arthur (Bradley James), likewise, has a less than stellar opinion of Merlin. After saving the prince's life Merlin becomes his servant and the two begin to respect and trust one another. Merlin eventually becomes close friends with Arthur, and another servant named Guinevere. But when Uther's actions eventually cause his ward Morgana to turn against Camelot, Merlin must work together with the Once and Future King to save Albion.

Het

 * Arwen- Arthur and Gwen
 * Gwencelot - the ship between Gwen and Lancelot
 * Mergana- the ship between Merlin and Morgana
 * Merthian- the ship between Merlin and Princess Mithian

Slash

 * Merthur - the ship between Merlin and Arthur
 * Merwaine - the ship between Merlin and Gwaine
 * Perwaine- the ship between Percival and Gwaine
 * Mercelot- the ship between Merlin and Lancelot

Femslash

 * Morgwen - the ship between Morgana and Gwen
 * Morgana/Morgause - the ship between Morgana and Morgause

Fandom
AO3