Bristol, city and unitary authority, southwestern England. The historic centre of Bristol and the sections of the city north of the River Avon (Lower, or Bristol, Avon) were part of the historic county of Gloucestershire, while the areas south of the Avon lay within the historic county of Somerset until the creation of the county of Bristol (1373–1974) and then of the county of Avon (1974 …

https://www.britannica.com/place/Bristol-England