Guillaume de Cahaignes, a French knight who participated in the Norman conquest of England, and lord of what is now Cahagnes, was given Milton in Buckinghamshire and the Sussex village of Horstede (The Place of Horses in Old English). The latter became Horstede de Cahaignes and in time Horsted Keynes. The place name is first attested in the Domesday Book of 1086. The village has been formally twinned with the Normandy village of Cahagnes since 1971. The Horsted Cahagnes Society promotes social and cultural links, and organises annual exchange visits between the two places.