The son of Meliodas & Isabelle. He was educated in France; faught for his uncle, King Mark, against the King of Ireland's champion & defeated him; travelled incognito to Ireland to have his wounds healed; fell in love with the King's daughter Iseult; was forced to return to Cornwall when his identity was discovered; fell out with his uncle over an affair with a young girl; spent some time at King Arthur's court; was obliged to travel again to Ireland to gain Iseult's hand in marriage to Mark; accidentally drank love potions meant for Mark & Iseult; became Iseult's lover despite her marriage to his uncle (and had four children); left for Brittany when things became too hairy; married King Hoel Mawr (the Great) of Brittany's daughter, also Iseult; got wounded in a fight; sent for his old lover to cure him; being told by his wife that she had refused to come, he died; Iseult comitted suicide and the two were buried together.
Despite a number of Tristram Sites having been identified in the West Country, some historians believe that his story has been transferred to Cornwall from Northern Britain. Lyonesse, in its earliest form, appears as Liones, a name very similar to early forms of Lothian. Tristram is a form of the Pictish name, Drustan, and a Pictish Prince named Drustan ipe Talorg appears in Welsh records as a late 3rd century ancestor of the Kings of Gwynedd.
Generally considered historical.