Cheldric, 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.
Sources
Historia Regum Britanniae | Geoffrey of Monmouth, c. 1138
Roman de Brut | Wace, c. 1155
Brut | Layamon, late 12th century to mid-13th century
Alliterative Morte Arthure | c. 1400
The Misfortunes of Arthur | Thomas Hughes, 1587