Aumagwin
In lines 311-341 of Erec and Enide, Chrétien de Troyes names King Amauguin among Arthur’s allies and advisors.
Almost certainly, he is identical with the Amauguin found among Arthur’s knights in the list beginning in line 1691 of the same work.
He’s also mentioned in Henrich’s Diu Crône. Among the two romances, Erec and Diu Crône, he appears as a white stag hunt and two chastity tests. His lover, Lady Aclamet, failed in one of the latter.
He was defeated by Sir Gasozein of Dragoz while traveling in Arthur’s company.
Sources
Erec | Chrétien de Troyes, late 12th century
Diu Crône | Heinrich von dem Türlin, c. 1230