The name of the Aire is first attested as "Yr" in a charter from 959 AD (as edited in Gray's "Cartularium Saxonicum"). The river is named as "darcy" and "ðarcy" (with the ancient eth) in a thirteenth-century transcription of a charter of 963. It is "Eyr’" in 1135 in "The Coucher Book of Selby" and other sources up to 1298. "Eir" is given in 1175-7 in one of the Dodsworth Manuscripts in Farrer's "Early Yorkshire Charters". A range of other spellings are attested, among them "Air" from c. 1160 to 1577 and John Cossins' 1775 "Plan of the Town of Leedes", and "Air’" from the thirteenth century to the fourteenth.