Historically part of Lancashire, Rochdale's recorded history begins with an entry in the Domesday Book of 1086 under "Recedham Manor". The ancient parish of Rochdale was a division of the hundred of Salford and one of the largest ecclesiastical parishes in England, comprising several townships. By 1251, Rochdale had become important enough to have been granted a Royal charter. Rochdale flourished into a centre of northern England's woollen trade, and by the early 18th century was described as being "remarkable for many wealthy merchants".
Rochdale rose to prominence in the 19th century as a mill town and centre for textile manufacture during the Industrial Revolution. It was a boomtown of the Industrial Revolution, and amongst the first industrialised towns. The Rochdale Canal—one of the major navigable broad canals of the United Kingdom—was a highway of commerce during this time used for the haulage of cotton, wool and coal to and from the area. The socioeconomic change brought by the success of Rochdale's textile industry in the 19th century led to its rise to borough status and it remained a dominant settlement in its region. However, during the 20th century Rochdale's spinning capacity declined towards an eventual halt.
Rochdale is the birthplace of the modern Co-operative Movement, to which more than one billion people worldwide belonged in 2012. The Rochdale Equitable Pioneers Society was founded in 1844 by 28 local residents as a response to the high cost and frequent adulteration of basic foodstuffs by shopkeepers at the time. The Pioneers were notable for combining the notion of the patronage dividend alongside investing trading surplus for member benefit, especially in education. The Rochdale Principles, the set of ideals which underpinned the society, are still used, in updated form, by the International Co-operative Alliance. The Rochdale Pioneers shop was the precursor to The Co-operative Group, the largest consumer co-operative in the world.
Rochdale today is a predominantly residential town. Rochdale Town Hall—a Grade I listed building—dates from 1871 and is one of the United Kingdom's finest examples of Victorian Gothic revival architecture.
Rochdale seems to be named from its position on the River Roch but is recorded as Recedham in the Domesday Book. The name is derived from Old English reced meaning "hall", and ham, a "homestead". Over time, the name changed to Rachedale and eventually Rochdale. The river's name is a back-formation from the Old English name, its name is //, with a long o. Rochdale however, is pronounced //, with a short o.