"This parish, formerly in the north-eastern division of Stockton ward, is bounded on the north by Coxhoe and Cornforth, on the north-west by Croxdale parish, on the west by Merrington, on the south-west by Aycliffe, on the south by Sedgefield, and on the east by Sedgefield and Trimdon. It comprises the townships of Bishop Middleham and Mainsforth, whose united area is 4126 statute acres. The population in 1851 was 1719, and in 1891, owing to the formation of several new parishes which took away the most populous parts, it only amounted to about 600.
"Bishop Middleham is a township and village in the parish of the same name, comprising an area of 2023 acres, and its annual value is £2794, 10s.
"The village of Bishop Middleham is irregularly built on the sides of two declivities and in the valley between them, and is about nine miles south-east from Durham, and two miles from the Ferrryhill station, on the main line of the North-Eastern Railway. The village contains four public houses, a brewery, and a few tradesmen's shops. It has a very primitive appearance; several of the dwelling-houses and cottages, with their antique sun-dial in front, bearing marks of great age. The village feast is held annually on Michaelmas day. A halmote court was held once a year, alternately with Cornforth and Sedgefield. of the once noble Castle of Middleham few vestiges now remain. portions of the massive foundations still to be seen bear witness of its former strength and magnitude.
"Mainsforth is a township and hamlet, comprising 627 acres, and its annual value is £1398. The hamlet of Mainsforth occupies an open and airy situation, three miles north-west of Sedgefield, and at about an equal distance between Bishop Middleham and Ferryhill railway station.
"Cornforth is a parish formed in 1868 entirely out of that of Bishop Middleham, with the exception of a small portion of Cassop-cum-Quarrington township, wherein is situated the village and colliery of Tursdale, formerly in the ancient parish of Kelloe. The parish also embraces the township of Thrislington, formerly in Bishop Middleham parish, and has a total area of 2698 acres, with a population of 4200, almost entirely of the mining class. The bulk of the population is contained in the village of West Cornforth, in addition to which there are the villages of Cornforth and Tursdale."
[From History, Topography and Directory of Durham, Whellan , London, 1894]