Herlewin is a resident of Britain. He has a wife.
During the events of Camelot: Season 1 Episode 6 Three Journeys played by Nick Devlin
Leontes, Gawain, Kay, and Merlin discover a raided camp and find Herlewin still alive, but his wife dead. Merlin tells Herlewin that he is dying and Kay asks Merlin to use his powers. Merlin refuses to and Gawain snaps Herlewin's neck.