An evil knight in Diu Crône.
He raped a noblewoman, for which he was arrested by Gawain, tried at Arthur’s court, imprisoned, and exiled in disgrace. As a result, he harbored a hatred for Gawain and later, through trickery, managed to steal Gawain’s horse.
The same character appears in Wolfram’s Parzival as Urjans.
Source
Diu Crône | Heinrich von dem Türlin, c. 1230