The Fracture That Ends the Fellowship

In Malory's Le Morte Darthur, the affair between Guinevere and Lancelot is not merely a private matter but the specific mechanism that destroys the Round Table. Mordred and the knight Agravain expose the lovers to force Arthur's hand, precipitating Guinevere's trial and near execution for treason, a sentence Lancelot interrupts by force, killing several of his fellow knights, including Gareth and Gaheris, in the rescue, an act that turns their brother Gawain from Lancelot's staunch defender into his implacable enemy and drags Arthur into a war against the very knight who has been his kingdom's greatest defender. That war is what pulls Arthur out of Britain and leaves Mordred as regent, the opening Mordred needs to seize the throne and, in some versions, Guinevere herself, precipitating the campaign that ends at the Battle of Camlann. Guinevere's own ending is deliberately quiet against that scale of consequence: she takes the veil at Amesbury as Arthur's kingdom collapses around her, and when Lancelot comes to her one last time, she refuses him, choosing a life of penance over a reunion, a final scene Malory gives real weight to as the one act of the whole tragedy that is entirely her own choice.