The parish comprised Middleton, Pilsworth, Hopwood, Thornham, Great Lever, Ashworth, Ainsworth and Birtle-cum-Bamford, the last four being detached from the main parish.
The original parish church or chapel was built before 1066 and was dedicated to St Cuthbert, following the Norman Conquest a new church was built and dedicated to St Leonard. However, there is still a side chapel dedicated to St Cuthbert.
The church was entirely rebuilt in the early fifteenth century by Cardinal Thomas Langley, Lord Privy Seal and archdeacon of York, who was a native of Middleton. His building incorporated some remains of earlier building such as the arch between the tower and the nave (thought to be twelfth century).
The church building underwent further reconstruction a century later when Richard Assheton, lord of the manor of Middleton, enlarged it considerably and added the clerestory.
Subsequent rebuilding included the addition to the tower of its unusual wooden cap. The church retains many early features, however, including the rood screen and other early woodwork, together with some stained glass.
The advowson always belonged to the owner of the manor of Middleton which remained in the Assheton family for centuries. Many of the sixteenth-century rectors of the parish were family members.
Coal mines in Thornham and Hopwood helped to fuel the development of the textile industry which flourished with other industry in the parish from the late eighteenth century. Middleton is now part of the Manchester conurbation.
Cardinal Langley founded a church school which moved in 1586 to a new building which still stands on the bank of the River Irk.
Sir Stephen R. Glynne, Bart., Notes on the churches of Lancashire, ed. James Augustus Atkinson, (Chetham Society, new series, 27, 1893).
Victoria County History online: https://www.british-history.ac.uk/vch/lancs/vol5/pp151-161