It is located on the River Cam approximately 55 miles (89 km) north of London. As of the 2021 United Kingdom census, the population of Cambridge was 145,700.[2][a] 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.