Gaheris 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.

King Lot, also spelled Loth or Lott, is a British monarch in Arthurian legend. He was introduced in Geoffrey of Monmouth's pseudohistorical Historia Regum Britanniae as King Arthur's brother-in-law, who serves as regent of Britain between the reigns of Uther Pendragon and Arthur. He has appeared regularly in works of chivalric romance, alternating between the roles of Arthur's enemy and ally, and is often depicted as the ruler of Lothian and either Norway or Orkney. His literary character is probably derived from hagiographical material concerning Saint Kentigern, which features Leudonus as king of Leudonia and father of Saint Teneu.