the name "yr" is documented in gray's "cartularium saxonicum" in 959 ad. the river is "darcy" and "ðarcy" (with the ancient eth) in 963, in the same source. 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". "air" from "c." 1160 to 1577, "air’" in the thirteenth century. in john cossins' 1775 "plan of the town of leedes" it is labelled "river air".