Gasoain, Gasosin, Gosenain, Goswain
A Knight of the Round Table from the land of Estrangorre.
We learn in the Vulgate Merlin that as a young man, he fought with Gawain against the Saxons invading Britain, and was knighted by Arthur for his service. He apparently quarrelled with Gawain after one accused the other of being a traitor.
Later, he accompanied Gawain on a mission to check on a report that the castle Dolorous Guard had been liberated by Lancelot, and he was captured and imprisoned in the Dolorous Prison by Brandin of the Isles (Brandus des Illes). Lancelot rescued him from here, and also from the prison of the evil Tericam (Turquine).
He may appear in Heinrich von dem Türlin’s Diu Crône as Gasozein of Dragoz.
Sources
Lancelot do Lac | 1215-1220
Vulgate Merlin | 1220-1235
Arthour and Merlin | Late 13th century