Anne Arundel County (/əˈrʌndəl/), also notated as AA or A. A. County, is a county located in the U. S. state of Maryland. As of the 2010 United States 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 (1615–1649), a member of the ancient family of Arundells in Cornwall, England, and the wife of Cecilius Calvert, 2nd Baron Baltimore (1605–1675), founder and first Lord Proprietor of the colony Province of Maryland.