Edward of Carnavron
Edward of Orkney
Edward of the Red Castle
A knight who, with his brother Sir Hugh (Hue), stole lands from the Lady of the Rock. Yvain championing the lady, called for a duel against one of the brothers, but the brothers insisted that Yvain fight them both at the same time. Yvain won the battle, killing Edward and wounding Hugh.
Another source of mine says Sir Marhaus fought and won the lands back.