The Greek polis: concept and political organization

The polis was the characteristic form of political organization in classical Greece: an autonomous community of citizens comprising an urban core and its surrounding agricultural territory (the chora). It typically had an acropolis, a fortified elevation with defensive and religious functions, and an agora, a public space for commerce, politics, and social life. Each polis was a sovereign entity with its own laws, magistracies, religious calendar, and military forces, which explains the enormous political fragmentation of the Greek world, never politically unified in antiquity except by outside conquest.