Godmanchester is a small town and civil parish within the Huntingdonshire district of Cambridgeshire, in England. It lies on the south bank of the River Great Ouse, south of the larger town of Huntingdon, and on the A14 road.
The town was on the site of the Roman town of Durovigutum. It was first chartered by King John in 1212, though it had been a market town and royal manor for some years. There is archaeological evidence of Celtic and earlier habitation prior to the establishment of a key Roman town and a Mansio (inn), so the area has probably been continuously occupied for more than 2000 years. The settlement was at a crossroads of Roman roads, with Ermine Street, the Via Devana (from Cambridge, between Colchester and Chester) and a military road from Sandy, Bedfordshire, all passing through. The Roman settlement was sacked by Anglo-Saxons in the third century. In contrast to Huntingdon, there have been vast amounts of archaeological finds in the centre of Godmanchester, which has two conservation areas with a large number of timber-framed Tudor houses, the largest being Tudor Farm, dating from 1600 and restored in 1995.
The mansio is mentioned in Godmanchester's name, which comes from Anglo-Saxon Godmundceaster, meaning a "town or Roman buildings associated with a man called Godmund". The location is likely to have been originally settled due to the gravel beds providing a ford across the River Great Ouse. In 2003 it had a population of about 5500 in 3500 homes, with the largest increase in population occurring between 1981 and 1991 (81%) with more modest growth since.
There are several bridges across the Great Ouse to Huntingdon, but until 1975 Old Bridge, Huntingdon, a medieval bridge, was the only one. It is now used only for light traffic, and a parallel footbridge has been built for pedestrians. Construction of the A14 bypass means that heavy traffic now flows over a modern bridge.
Between Godmanchester, Huntingdon and Brampton lies England's largest meadow, Portholme, which remains an important flood plain but which has served as an equestrian racecourse and centre for early aviation.
Original historical documents relating to Godmanchester, including the original church parish registers, local government records, maps, photographs and the surviving borough charters, are held by Cambridgeshire Archives and Local Studies at the County Record Office Huntingdon.