Dorchester ( DOR-ches-tər) is the county town of Dorset, England. It is situated between Poole and Bridport on the A35 trunk route. An historic market town, Dorchester is on the banks of the River Frome to the south of the Dorset Downs and north of the South Dorset Ridgeway that separates the area from Weymouth, 7 miles (11 km) to the south. The civil parish includes the experimental community of Poundbury and the suburb of Fordington.
The area around the town was first settled in prehistoric times. The Romans established a garrison there after defeating the Durotriges tribe, calling the settlement that grew up nearby Durnovaria; they built an aqueduct to supply water and an amphitheatre on an ancient British earthwork. After the departure of the Romans, the town diminished in significance, but during the medieval period became an important commercial and political centre. It was the site of the "Bloody Assizes" presided over by Judge Jeffreys after the Monmouth Rebellion, and later the trial of the Tolpuddle Martyrs.
In the 2011 census, the population of Dorchester was 19,060, with further people coming from surrounding areas to work in the town which has six industrial estates. The Brewery Square redevelopment project is taking place in phases, with other development projects planned. The town has a land-based college, Kingston Maurward College, The Thomas Hardye School, three middle schools and thirteen first schools. The Dorset County Hospital offers an accident and emergency service, and the town is served by two railway stations. Through vehicular traffic is routed round the town by means of a bypass. The town has a football club and a rugby union club, several museums and the biannual Dorchester Festival. It is twinned with three towns in Europe. As well as having many listed buildings, a number of notable people have been associated with the town. It was for many years the home and inspiration of the author Thomas Hardy, whose novel The Mayor of Casterbridge uses a fictionalised version of Dorchester as its setting.