Cambridge is a city and non-metropolitan district in the county of Cambridgeshire, England. It is the county town of Cambridgeshire and is located on the River Cam, 55 miles (89 km) north of London. As of the 2021 United Kingdom census, the population of the City of Cambridge was 145,700; the population of the wider built-up area was 181,137. Cambridge became an important trading centre during the Roman and Viking ages, and there is archaeological evidence of settlement in the area as early as the Bronze Age. The first town charters were granted in the 12th century, although modern city status was not officially conferred until 1951.