Rhuawn the Radiant, Rhufawn Befr, Rhufawn the Radiant, Ruawn Pebyr
An Arthurian warrior who was the son of Deorthach or Gwyddno.
He is probably identical with a northern british prince or hero. There are several mentions of the name Ruawn and a prince who died young.
He is one of the Three Fair Princes of the Island of Britain in Triad no. 3, and one of the three Three Golden Corpses of the Island of Britain.
Rhonabwy says he is an advisor to Arthur and a brilliantly clad horseman.
Sources
Culhwch and Olwen | Late 11th century
Triads of the Island of Britain (Welsh ”Triads”) | 11th century to 14th century
Breudwyt Rhonabwy | 13th century