Gérard D’Athée was a mercenary captain employed by King John of England from 1211 to 1215 to control southern Wales.
He served King John in France as commander of Loches castle, one of the last castles to resist Philip Augustus in Normandy. D'Athée was captured by the French and, being so highly valued by King John, ransomed back to England in return for 1,000 marks. His kinsmen were granted estates in England, and D'Athée was appointed High Sheriff of Gloucestershire and Herefordshire (1208-1210) and High Sheriff of Nottinghamshire, Derbyshire and the Royal Forests in 1209. His rise in the English court caused resentment amongst the English barons. He is mentioned critically in clause 50 of the Magna Carta:
We will entirely remove from their bailiwicks, the relations of Gerard of Athee (so that in future they shall have no bailiwick in England); namely, Engelard of Cigogné, Peter, Guy, and Andrew of Chanceaux, Guy of Cigogné, Geoffrey of Martigny with his brothers, Philip Marc with his brothers and his nephew Geoffrey, and the whole brood of the same.