The title of Earl of Cornwall was created several times in the Peerage of England before 1337, when it was superseded by the title Duke of Cornwall, which became attached to heirs-apparent to the throne.
Cadoc of Cornwall 1066+ (only attested by William of Worcester four centuries later)
Brian of Brittany (c. 1040-1084 or 85), resigned c. 1072
Robert, Count of Mortain (c. 1038–1095), half-brother of William the Conqueror.
William, Count of Mortain (1084–1140), peerage forfeit 1106
Alain de Bretagne, 1st Earl of Cornwall (died 1146), deprived 1141, nephew of Brian
Reginald de Dunstanville, 1st Earl of Cornwall (died 1175), illegitimate son of King Henry I of England.
John de Dunstanville, 2nd Earl of Cornwall (died after 1175), son
Baldwin de Redvers (died 1188), nephew
Henry FitzCount, Earl of Cornwall (c. 1175–1222), resigned peerage 1220, uncle
Richard, 1st Earl of Cornwall), second son of John, King of England, King of the Romans (1209–1272)
Edmund, 2nd Earl of Cornwall (1249–1300), son
Piers Gaveston, 1st Earl of Cornwall (1284–1312)
John of Eltham, Earl of Cornwall (1316–1336), second son of king Edward II of England and his queen Isabella of France.
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