The dead brother of a maiden championed by Gawain.
Mahardi was scheduled to fight a warrior named Reimambram of Zadas in order to save his sister, Behalim, from his clutches. Mahardi perished before the combat could take place, and Gawain, who arrived at their castle of Sempharap just in time, agreed to fight in Mahardi’s stead. Gawain was victorious.
Source
Diu Crône | Heinrich von dem Türlin, c. 1230