The history of Manchester encompasses its change from a minor township in Lancashire to an industrial metropolis in the United Kingdom and the world. Manchester began expanding "at an astonishing rate" around the turn of the 19th century as part of a process of unplanned urbanisation brought on by a boom in textile manufacture during the Industrial Revolution. The transformation took little more than a century.

Having evolved from a Roman castrum in Celtic Britain, in the Victorian era Manchester was a major locus of the Industrial Revolution, and was the site of one of the world's first passenger railway stations as well as important scientific achievements. Manchester also led the political and economic reform of 19th-century Britain as the vanguard of free trade.Asa Briggs, Victorian cities (1965) pp 83-136pp The mid-20th century saw a decline in Manchester's industrial importance, prompting a depression in social and economic conditions. Subsequent investment, gentrification and rebranding from the 1990s onwards changed its fortunes and reinvigorated Manchester as a post-industrial city with multiple sporting, broadcasting and educational institutions.

Manchester has been on a provisional list for UNESCO World Heritage City on numerous occasions. However, since the 1996 bombing, local authorities have persisted on a course of economic evolution rather than prioritising the past. This economic evolution is perhaps best illustrated with the Beetham Tower which instantly "torpedoed" any possibility of World Heritage City status according to one author. Despite this, areas perceived as internationally important in the Industrial Revolution, such as Castlefield and Ancoats, have been sympathetically redeveloped.

Toponymy The name Manchester originates from the Latin name Mamucium or its variant Mancunio. These names are generally thought to represent a Latinisation of an original Brittonic name. The generally accepted etymology of this name is that it comes from Brittonic *mamm- ("breast", in reference to a "breast-like hill").The Cambridge Dictionary of English Place-Names Based on the Collections of the English Place-Name Society, ed. by Victor Watts (Cambridge: Cambridge University Press, 2004), under MANCHESTER.Hylton (2003), p. 6. However, more recent work suggests that it could come from *mamma ("mother", in reference to a local river goddess). Both usages are preserved in Insular Celtic languages, such as mam meaning "breast" in Irish and "mother" in Welsh. The suffix -chester is from Old English ceaster ("Roman fortification", itself a loanword from Latin castra, "fort; fortified town").

The Latin name for Manchester is often given as Mancuniun. This is most likely a neologism coined in Victorian times, similar to the widespread Latin name Cantabrigia for Cambridge (whose actual name in Roman times was Duroliponte).

Prehistory

Prehistoric evidence of human activity in the area of Manchester is limited, although scattered stone tools have been found.Nevell (2008), p. 11.

There is evidence of Bronze Age activity around Manchester in the form of burial sites. Although some prehistoric artefacts have been discovered in the city centre, these have come from redeposited layers, meaning they do not necessarily originate from where they were found; wider evidence has been found for activity in other parts of the borough.Nevell (2008), p. 12. Before the Roman invasion of Britain, the location lay within the territory dominated by the Brigantes and prior to the Roman conquest of the area in the 70s AD, it was part of the territory of the Brigantes, a Celtic tribe, although it may have been under the control of the Setantii, a sub-tribe of the Brigantes.Kidd (1996), p. 12.

For the important prehistoric farm site at Oversley Farm, see .

Roman

The Roman fort of Mamucium was established c. AD 79 near a crossing point on the River Medlock.Gregory (2007), pp. 1, 3. The fort was sited on a sandstone bluff near the confluence of the rivers Medlock and Irwell in a naturally defensible position.Gregory (2007), p. 1. It was erected as a series of fortifications established by Gnaeus Julius Agricola during his campaign against the Brigantes who were the Celtic tribe in control of most of what would become northern England.Mason (2001), pp. 41–42. It guards the Deva Victrix (Chester) to Eboracum (York) Roman road running east to west, and a road heading north to Bremetennacum (Ribchester).Gregory (2007), pp. 1–2. The neighbouring forts were Castleshaw and Northwich.Walker (1999), p. 15. Built first from turf and timber, the fort was demolished around 140. When it was rebuilt around 160, it was again of turf and timber construction.Gregory (2007), p. 3. In about 200 the fort underwent another rebuild, this time enhancing the defences by replacing the gatehouse with a stone version and facing the walls with stone.Philpott (2006), p. 66. The fort would have been garrisoned by a cohort, about 500 infantry, of auxiliary troops. Retrieved on 20 July 2008.

Evidence of both pagan and Christian worship has been discovered. Two altars have been discovered and there may be a temple of Mithras associated with Mamucium. A word square was discovered in the 1970s, which may be one of the earliest examples of Christianity in Britain.Shotter (2004), p. 129. A civilian settlement (the first in Manchester), or vicus, grew in association with the fort, made up of traders and families of the soldiers. An area that has a concentration of furnaces and industrial activity has been described as an industrial estate.Shotter (2004), p. 117. The vicus was probably abandoned by the mid 3rd century, although a small garrison may have remained at Mamucium into the late 3rd and early 4th centuries.Gregory (2007), p. 190. The Castlefield area of Manchester is named after the fort.

Post-Roman

Once the Romans left Britain, the focus of settlement in Manchester shifted to the confluence of the rivers Irwell and Irk.Hylton (2003), pp. 3, 8. During the Early Middle Ages that followed – and persisted until the Norman Conquest – the settlement of Manchester was in the territory of several different kingdoms.Hylton (2003), p. 7. In the late 6th and early 7th centuries, the kingdom of Northumbria extended as far south as the River Mersey, south of what was then the settlement of Manchester. Etymological evidence indicates that the areas to the north west of Manchester (such as Eccles and Chadderton) were British while the parts of Manchester (such as Clayton, Gorton and Moston) were Anglian, and the south west of Manchester was Danish (including Cheadle Hulme, Davyhulme, Hulme and Levenshulme).

Between the 6th and 10th centuries, the kingdoms of Northumbria, Mercia and Wessex struggled for control over North West England. In 620, Edwin of Northumbria may have sacked Manchester, and the settlement may have been sacked again in 870 by the Danes.Hylton (2003), p. 8. According to legend, Nico Ditch – which runs east–west from Ashton-under-Lyne to Stretford and passes through Gorton, Levenshulme, Burnage, Rusholme, Platt Field Park in Fallowfield, Withington and Chorlton-cum-Hardy – is a defence against Viking invaders and was dug in 869–870. Whether this is true is uncertain, but the ditch does date from between the 7th and 9th centuries.Nevell (1992), pp. 77–83. The Anglo Saxon Chronicle detail that in 919 Edward the Elder sent men "to Mameceaster, in Northumbria, to repair and man it"; this probably refers to a burh at Manchester as an advanced post of Mercia. Although it is unsure where the site is, it is possibly a reference to the Roman fort. In 1055, most of what later became Lancashire was under the control of Tostig.

The ancient parish of Manchester covered a wider area than today's metropolitan borough (although not including its full extent), and was probably established in the Anglo-Saxon period (there were at that time only two churches in the parish: at Manchester and Ashton-under-Lyne). Forty distinct townships developed in the parish and in medieval times the royal manor of Salford was the most important of these.

Medieval

Manchester was administratively part of the Salford Hundred.Kidd (1996), p. 13. In 1086 the hundred covered about and had a population of about 3,000.Hylton (2003), p. 10. It was given to Roger de Poitou; Roger divided the hundred into fiefdoms and made the Gresle family barons of Manchester. Albert de Gresle was the first baron of Manchester. Although the Gresle family did not reside at the manor, Manchester continued to grow in their absence and stewards represented the lords of the manor.

Manchester's entry in the Domesday Book reads "the Church of St Mary and the Church of St Michael hold one carucate of land in Manchester exempt from all customary dues except tax".Hylton (2003), p. 9. St Mary's Church was an Anglo-Saxon church on the site of Manchester Cathedral; St Michael's Church may have been in Ashton-under-Lyne. The parish of Manchester – of which St Mary's Church was a part – was the ecclesiastical centre of the Salford Hundred. It covered about and extended as far as the edges of Flixton and Eccles in the west, the Mersey between Stretford and Stockport in the south, the edge of Ashton-under-Lyne in the east, and the edge of Prestwich in the north. That such a large area was covered by a single parish has been taken as evidence of the area's "impoverished and depopulated status". The only tax the parish was subject to was Danegeld.

There was a castle in Manchester overlooking the rivers Irk and Irwell, where Chetham's School of Music stands today. This castle was probably a ringworkNewman (2006), p. 141. and has been described as "of no political or military importance". By the late 13th century, the Grelleys or Gresles, who were barons of Manchester for two centuries, had replaced the castle with a fortified manor house. They used the house as the administrative centre of the manor.Kidd (1996), p. 14. While the town was owned by the lords of the manor, they directly leased land to tenants and created burgage tenements for indirect rent; as well as containing a house, these plots of land could also contain workshops and gardens. The family also owned the only corn mill in the manor which was used by all the tenants of the manor to grind their corn. Medieval Manchester was centred on the manor house and the Church of St Mary mentioned in the Domesday Book. As well as a castle at Manchester, there was also one in Ringway. Ullerwood Castle, a motte-and-bailey, probably dates from the 12th century and was owned by Hamon de Massey who owned several manors in the north east of Cheshire.Nevell (1997), p. 27, 33, 35.