Jarl

Jarl was an unscrupulous slave trader who operated in the kingdom of Cenred, near the border to Camelot

Biography
He and King Cenred had an "I won't bother you, you won't bother me" agreement. Jarl captured Gwaine who soon became his champion in the slave fights. On their way to find the Cup of Life, Arthur and Merlin were captured and met up with Gwaine. Jarl decided he wants to see a fight and chose Merlin to face his champion, Arthur volunteered instead, there Gwaine revealed he was the champion. As Arthur and Gwaine fought, Merlin intervened by setting the wires that hanging above everyones head on fire with Magic. Merlin, Gwaine and Arthur managed to escape and head towards the Druids. Jarl then looked through Arthur's bag which was confiscated, finding out that he was prince of Camelot. Jarl had informed Cenred of the way Arthur and friends were headed. When he requested compensation, Morgause gave him it and used magic to knock him into a wall, seemingly killing him. (The Coming of Arthur: Part One)