COLNBROOK, a chapelry, and formerly a market-town, partly in the parish of Stanwell, hundred of Spelthorne, county of Middlesex, but chiefly in the parishes of Horton, Iver, and Langley-Marish, hundred of Stoke, union of Eton, county of Buckingham, 46 miles (S. E. by S.) from Buckingham, and 17 (W. by S.) from London, on the road to Bath; containing 1050 inhabitants. This place, which is of great antiquity, is supposed to have been the station Ad Pontes of Antoninus: it derives its name from the river Colne, by which it is separated from Middlesex, and is intersected by different branches of that river, over each of which is a small bridge. The town consists principally of one long street, and the houses are in general neatly built, and of respectable appearance. The trade chiefly arises from its situation as a great thoroughfare, and till lately it was a considerable posting town; it is about a mile and three-quarters distant from the Great Western railway. The market has long been discontinued, and the market-house and the chapel, which were inconveniently situated in the narrower part of the town, have been removed by the commissioners of the turnpikeroads, who have built a new chapel, a neat edifice, dedicated to St. Mary. Fairs are held on April 5th and May 3rd, for cattle and horses. The government, by charter of Henry VIII., renewed in the reign of Charles I., is vested in a bailiff and burgesses. The living is a donative; net income, £103; patrons, Trustees of the late George Townsend, Esq., for fellows of Pembroke College, Oxford. There is a place of worship for Baptists; and several charitable bequests have been made, the principal of which is one by Thomas Pitt, in the year 1657, of some land now producing £32 per annum, for distribution among the poor.