Clarion was the King of Northumberland, with his capital at Belande. He was one of the kings who joined the rebellion against King Arthur at the beginning of his reign. He pledged an army of 3,000 to the cause and they fought at the Battle of Bedegraine. However, after their defeat, his one-time Saxon allies invaded his lands and he was forced to return to repel them with the aid of Duke Escant of Cambernic. Later, defeated again by Arthur at Clarence, he appears to have made peace with the monarch and fought with him in his continental campaigns against Rome. He and his son, Sir Espinogres, were made Knights of the Round Table for their support. He is probably the King of Northumberland who attends a number of Arthurian tournaments including the jousting at Candlemas after the death of Lady Elaine of Astolat. Clarion brought a hundred knights and defeated King Howel of Brittany in the tilts.