Cambridge is a university city and the county town of Cambridgeshire, United Kingdom, on the River Cam approximately 55 miles north of London. At the United Kingdom Census 2011, the population of the Cambridge built-up area was 158,434 including 29,327 students. 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.