Geoffrey of Monmouth is the first to mention him. Layamon calls him "emperor" and seems to place him above the other Saxons. Cheldric arrived just in time to save Colgrim from Arthurís siege at York. Arthur defeated him at Lincoln and at Caledon Forest, after which Cheldric agreed to leave Britain.
Cheldric and the others betrayed Arthur, however, and landed again at Totnes. He conquered Somerset, Devonshire, Dorset, and Wiltshire before Arthur arrived and defeated him at Bath (Badon), where Colgrim and Baldulph were killed. Seeing the others fall, Cheldric fled into Scotland, but was pursued by Cador of Cornwall, who killed Cheldric at either the Isle of Thanet or at the river Teign. In an alternate version provided by John Hardyng, Arthur bestowed Cheldric with the country of Wessex after defeating him at Bath.
Cheldrich, Cheldrichus, Cheldrik, Childrik
A Saxon duke who allied with Mordred and brought thousands of Saxons into Britain to oppose King Arthur. Mordred promised him all lands north of the Humber river, and Kent, in return for his support. Arthur killed him at the battle of Camel.