Mador (Sir), a Scotch knight, who accused queen Guinever of having poisoned his brother.  Sir Launcelot du Lac challenged him to single combat, and overthrew him; for which service king Arthur gave the queen's champion La Joyeuse Garde as a residence. (The Reader's Handbook of Famous Names in Fiction, &c., Brewer, 1910)

    Mador de la Porte, "le frere Gaheris de Kareheu," III, 159; V, 100; 101; 236; VI, 249; 250; 253; 254; 255; 258; 260; 261; 262; 264; 266; 267; 268; 269; VII, 242,¹ a companion of the Round Table.
    Mador le Noir de l'Isle Noire, "li frere Adragain² li Bruns," III, 46; identical with Madoc, Mauduc le Noir de l'Isle Noire.
    ¹ The MS. No. 337 has here on fol. 248, col. b (page 242, line 7, of my vol. VII):  Madoc li Noire de la Porte.  I have mended Mador.  There is evidently here a confusion between Mador de la Porte and Madoc or Mauduc le Noir de l'Isle Noire, because the former is nowhere else named "li Noire" and the latter is in no other place described as: "de la Porte."
    ² In my mongraph The Structure of Le Livre d'Artus, etc., London, 1914, pages 21 and 22 I have shown that Adragain le Brun plays in the version represented by folios 1-115 in the MS. No. 337 the same part as Raolals in version represented by the second part.  I am inclined to think that Mador is in the passage above referred to but a mistake by a scribe for Madoc.
(The Vulgate Version of the Arthurian Romances, Sommer, 1916).