A city-state is a region controlled exclusively by a city, usually having sovereignty. Historically, city-states have often been part of larger cultural areas, as in the city-states of ancient Greece (such as Athens, Sparta and Corinth), the Phoenician cities of Canaan (such as Tyre and Sidon), the Mayans of pre-Columbian Mesoamerica (including sites such as Chichen Itza and El Mirador), the central Asian cities along the Silk Road (which includes Samarkand and Bukhara), or the city-states of Northern Italy (especially Florence and Venice). More recently the neologism citistate has been developed, referring to the city as the center of a 'city region' that includes relocated urban business like factory and company towns, and supply economies like agricultural, timber and mineral extraction whose commodities find a market in the city.
In modern times Hong Kong was a city-state colony of the British empire until 1997, and Singapore, Monaco and Vatican City arguably remain autonomous city-states.
Among the most creative periods in human history are those in which humanity organized itself in small independent centers. Modern Europe owes much of its civilization to two such periods -- the small Greek city-states, and the city-states of Renaissance Italy. However, these small creative groupings usually survived for only short periods of time because they lacked the size and strength to defend themselves against the onslaught of larger social entities. In addition, the success of small regional units coexisting as disunited parts of a loose geographical and cultural unity, as in Italy or Hellas (Greece), acted as a barrier to the creation of larger national units with greater staying power. Thus, they inevitably gave way to larger organizations of society, the empire and eventually the nation-state.
The term "city-state" should not be confused with that of "independent city", which refers to a city which is not administered as part of another local government area (eg, a county).