Edern ap Nudd

Edern ap Nudd (known variously as Ider son of Nuth, Yder and Isdernus) is a knight of King Arthur's court in Arthurian tradition. The earliest reference to Edern is in Culhwch ac Olwen, the oldest Arthurian prose tale, in which he appears in a long list of the personages of Arthur's traditional court at Celliwig; he appears in the early French romance poem Erec et Enide as a rival knight to the eponymous hero, as well as in the Welsh version of the tale, Geraint ac Enid, playing much the same role.

The later prose tale The Dream of Rhonabwy depicts Edern as one of Arthur's chief advisers at the Battle of Badon, in which he commands a "pure black troop" of Danish soldiers against the Saxons. He is the hero of the French romance Roman d'Yder, composed sometime between the twelfth and thirteenth centuries, in which he saves Arthur's life, joins his court and kills a bear with his own hands, earning the admiration of Guinevere and the jealous hostility of both Arthur and Sir Kay. Whilst travelling with Arthur, Gawain, Yvain and Kay, he slays two giants. A similar tradition appears in the twelfth century On the Antiquity of Glastonbury by William of Malmesbury which records that a young man named "Ider son of Nuth" was knighted at Caerleon on Christmas day and died of his wounds in battle against three giants on Brent Knoll in Somerset.