Edern ap Nudd
In early Arthurian tradition, Edern ap Nudd (English: Ider son of Nuth, French: Yder, Latin: Isdernus) is a knight of Arthur's court, appearing in a number of medieval Arthurian tales, including Culhwch ac Olwen, Breuddwyd Rhonabwy and, most prominently, in the romance of Geraint fab Erbin and its French equivalent Erec et Enide, in which he is one of the main antagonists of the title character. He is further identified with a warrior named Idernus depicted on the Porta della Pescheria of Modena Cathedral, and is associated with Brent Knoll in Somerset in English folklore.
He is the son of Nudd (sometimes written as Lludd) and is brother to both Creiddylad and the otherworldly warrior Gwyn ap Nudd.