Gaheris

Gaheris /ɡəˈhɛrɪs/ (Old French: Gaheriet, Gaheriés, Guerrehes, etc.) is a Knight of the Round Table in the chivalric romance tradition of Arthurian legend. A nephew of King Arthur, Gaheris is the third son of Arthur's sister or half-sister Morgause and her husband Lot, King of Orkney and Lothian. He is the younger brother of Gawain and Agravain, the older brother of Gareth, and half-brother of Mordred. His figure may have been originally derived from that of a brother of Gawain in the early Welsh tradition, and then later split into a separate character of another brother, today best known as Gareth. German poetry also described him as Gawain's cousin instead of brother.

Malory's Le Morte d'Arthur depicts Gaheris as little more than a supporting character to Gawain, with an odd exception of his murder of their mother. However, his role is greater in French prose cycles that were Malory's sources, including as an object of murderous sibling rivalry by his older brother Agravain in the Vulgate Cycle. Inevitably, both there and in Malory, Gaheris is killed alongside his other brother Gareth during Lancelot's rescue of Guinevere, the event that will lead to the fall of Arthur.