Somerville (pronunciation IPA: /ˈsʌmərvɪl/) is a city in Midlesex County, Massachusetts, just north of Boston. As of the 2000 census, the city had a total population of 77,478, and was the most densely populated municipality in New England, and the most dense in the United States outside the New York - New Jersey metropolitan area. It was established as a town in 1842, when it was separated from the urbanizing Charlestown.