In Malory, when Mordred & Agravain catch Guenever & Lancelot together, they have a small troop of warriors, all of whom end up dead, as does Agravain. The origins of the episode date back to at least the Mort Artu. But there are differences in the original.
   In the Mort Artu, Lancelot manages to kill and arm himself with the arms of a warrior called Tanaquin, and when he escapes, he kills only two of his assailants. Agravain escapes to be butchered with his brothers when Lancelot rescues Guinevere from the pyre.
   The differences in Malory's version can be traced back to the Stanzaic Morte Arthur. In it, Agravain is killed in the fight at the door, a dramatic event. This increases the power of Gawain's nobility and the depth of his sense of betrayal at the murder of Gareth & Gaheris, both unarmed here but maybe not in the Mort Artu. The Stanzaic Morte Arthur also gives us a bloodier struggle.
   Malory takes the next step and identifies the assailants. The role of Tanaquin from the Mort Artu is taken by Colgrevaunce, who in the other sources (including Malory's own usual errors!) should already have be dead as a result of his intervention in the fight between the brothers Bors and Lionel. The remainder of the warriors are Mordred, Agravain, Mador de la Porte, Meliot of Logris, Petipase of Winchelsea, Galleron of Galway, Melion of the Mountain, Astamor, Gromore Somir Jaure, Curselaine, and all three of Gawain's sons, Gingalin, Florence and Lovel. None are prominent warriors, for the most part. Galleron is known only as Gawain's adversary in The Adventures of the Tarn Wadling. Malory introduces him as the wounded knight who becomes Palimedes' godfather. Gingalin is the hero of Libaeus Desconnus. Gromore is the brother of Dame Ragnell. Colgrevaunce features prominently in the English version of Ywain. Meliot  appears as Nimue's cousin in the adventures as Arthur's wedding.