The giant who collected the beards of kings, and who challenged King Arthur and was defeated by him, appears in Geoffrey of Monmouth's History of the Kings of Britain. There he is called Retho, and lived on Mount Arvaius (Mount Snowdon). He was the strongest opponent Arthur had ever encountered until many years later he fought against the Spanish giant at Mont St.Michel, France (in a failed attempt to rescue a damsel in distress - she died when the giant tried to rape her).