User blog comment:Ḡwẵine Ḹٍٍkƨ Ĺiĸe Ͼềлȑềd/LEON/GWEN - Really weird idea about the Pendragon heir (spoilers)/@comment-5757581-20150517162721

Actually, according to some legends, Gawain/Gwaine would have been heir to the throne after Arthur's death, and I think (although I'm not sure) that some other versions of the story say that Galahad (who was disappointingly absent from the series) would be the heir to the throne of Camelot.