Anne Arundel County is a county located in the U.S. state of Maryland. As of the 2010 census, its population was 537,656, a population increase of just under 10% since 2000. Its county seat is Annapolis, which is also the capital of the state. The county is named for Lady Anne Arundell (1615–49), a member of the ancient family of Arundells in Cornwall, United Kingdom and the wife of Cecilius Calvert, second Baron and Lord Baltimore, (1605-1675), founder and first Lord Proprietor of the colony Province of Maryland.