Greoreas le Rous
A robber knight who abducted and raped a maiden in Chrétien de Troyes’s Perceval. Greoreas was defeated by Gawain and was forced to eat with hounds for a month as punishment, with his hands tied behind his back. Some time later, probably measurable in years, Greoreas was gravely wounded near the Galloway border. As I read the evidence, he must have tried the adventure of bringing the Haughty Maid of Logres her piebald palfrey and thus won his wounds from the Haughty Knight of the Rock on the Narrow Way. At this time Greoreas was traveling with a lady of his own. I cannot find nothing to indicate whether or not she was the one he had earlier forced, but surely her presence would not have prevented him from assisting any other damsel who asked his help.
In any case, his conqueror apparently appropriated his charger, leaving the pair with only the lady's palfrey (either a northern horse or a black one, depending on the ms. and the translator). Yet the conqueror left the wounded knight's lance and shield: it was the incongruity of seeing them hanging from a tree above a riding horse rather than a warhorse that first attracted Gawain to the place.
Too weak to recognize his one-time judge, Greoreas weakly warned him against crossing into Galloway, but begged him, if by any chance he should return alive from such an adventure, to check their condition and provide for the lady if he found her knight dead.
Gawain returned indeed, bringing not only the Haughty Maid of Logres but a powerful healing herb with which he bound up Greoreas' wounds, assisted by Greoreas' lady and using her fine white wimple for bandages. Immediately Greoreas felt strengthened enough to beg Gawain to bring him the nag yonder Ugly Squire was riding, so that he could get to a nearby priest in time to recieve the last sacraments. By the time Gawain brought the nag, Greoreas was sufficiently recovered not only to recognize his former judge, but to steal his horse Gringolet while Gawain was helping the lady onto her northern (or black) palfrey.
This treachery astonished Gawain, who had never recognized Greoreas; with Greoreas, old anger outweighed present gratitude, and he waited only long enough to reveal his identity and explain his revenge before riding after his already-disappearing lady. Both his knowing about the nearby pries, and his later sending his nephew, on Gringolet, to find Gawain and bring back his head, suggest that Greoreas was living in the vicinity.
After he was defeated in combat by Sir Durmart, Greoreas shunned his evil ways and humbly presented himself at Arthur’s court. In the Livre d’Artus, Greoreas is among Arthur’s warriors in the battle against the Saxons at Vambieres, though he still dislikes Gawain because of Gawain’s conflict with Greoreas’s cousin, Guinganbresil.
Having stolen Gawain's horse Gringolet, Greoreas mounted his nephew on the great steed and sent him to find Gawain and bring him back his head. The nephew found Gawain, mounted on the Ugly Squire's Sorry Nag, on the river bank facing the Rock of Canguin. Gawain waited for him and, although so much worse mounted, easily defeated him.
Presently Gawain gave his enemy's nephew to the Ferryman of Canguin, in lieu of his newly recovered Gringolet, to pay for the passage over the river. By rules of combat, the defeated man was his conqueror's prisoner. In any case, Greoreas' nephew would not appear to have lost by the transfer, for the brief battle had left him badly wounded; since the Ferryman treated him and Gawain with equal courtesy, like two guests rather than guest and prisoner, we can probably assume that the nephew's wounds were well cared for.