Gwallawg ab Llenawg

   In the Triads, we find him celebrated with Dunawd Fur and Cynvelyn Drwagl, as one of the pillars of battle of the Island of Britain, which is explained to mean that these chieftains were skilled in the disposition of the order of battle, and were battle leaders, superior to all others that ever existed.-Triad 71.
   And in a subsequent Triad, he is called one of the "Graveslaughtering ones," from his having avenged his wrongs from his grave.-Triad 76.
   His name occurs in Llywarch Hen's Elegy upon Urien Rheged; and he was one of the three northern kings, who united themselves with that prince for the purpose of opposing the progress of Ida's successors (the Angle kings of Northumbria).
   In Gruffydd ab Arthur's Historia (Geoffrey of Monmouth), he is mentioned as one of the knights who were present at Arthur's coronation;  and his death is recorded to have  taken place in the last conflict between that Sovereign and the Romans. The "Englynion y Beddau" place his tomb in Carrawc.