CHATTERIS, urban district and market town in the Isle of Ely, Cambridgeshire, England, 25 gym. N. by W. of Cambridge by the L.N.E.R. Pop. (193I) 5,153. The church of St. Peter is principally Decorated; and there are fragments of a Benedictine convent founded in the loth century and rebuilt after fire in the early 14th. To the north runs the great Forty-foot Drain, also called Vermuyden's, after the Dutch engineer, whose name is as sociated with the fen drainage works of the mid 17th century.