City-state

A city-state is an independent or autonomous entity, not administered as a part of another local government, whose territory consists of a city and possibly its surrounding territory. A city-state can also be defined as a central city and its surrounding villages, which together follow the same law, have one form of government, and share languages, religious beliefs, and ways of life.

On the Syfy original series Defiance, the U.S. city of St. Louis, Missouri was destroyed during the war that took place between the citizens of Earth and the alien alliance known as the Votons. After peace was made between the two cultures, a border town city-state was established, which became known as Defiance by the mid 21st century.