city-state, in ancient Greece, Italy, and Medieval Europe, an independent political unit consisting of a city and surrounding countryside. The first city-states were in Sumer, but they reached their peak in Greece. From the beginning of Greek history to its climax in the 5th and 4th cent. B.C., the Greeks were organized into city-states, of which there were several hundred. The first Italian city-states were Greek colonies. Later Etruscan and native city-states emerged, including Rome. After the fall of the Roman Empire, many Italian cities (e.g., Florence, Genoa, Venice) were city-states until the 19th cent., as were such N German cities as Bremen and Hamburg. The Greek word polis meant both city and city-state. Since the city-state was independent, different states—and the same state at different times—had a variety of governments, ranging from absolute monarchy to pure democracy. Only citizens participated in the government of the city-state, and citizenship was limited to those born of citizen parents. In the classical era, a large proportion of the city-state's population consisted of slaves. Participation by citizens in government was often limited by class distinctions. The government usually consisted of an assembly and council; the former predominated in democracies, the latter in oligarchies. Although the various city-states combined into religious or military federations, most did not endure for long in Greece, leaving it open to foreign attack by large centralized states to which it eventually submitted.

Political system consisting of an independent city with sovereignty over a fixed surrounding area for which it served as leader of religious, political, economic, and cultural life. The term was coined in the 19th century to describe ancient Greek and Phoenician settlements that differed from tribal or national systems in size, exclusivity, patriotism, and ability to resist incorporation by other communities. They may have developed when earlier tribal systems broke down and splintered groups established themselves as independent nuclei circa 1000–800 BC; by the 5th century BC they numbered in the hundreds, with Athens, Sparta, and Thebes among the most important. Incapable of forming any lasting union or federation, they eventually fell victim to the Macedonians, the Carthaginians, and the Roman empire. In the 11th century the city-state revived in Italy; the success of medieval Italy's city-states, including Pisa, Florence, Venice, and Genoa, was due to growing prosperity from trade with the East, and several survived into the 19th century. Germany's medieval city-states included Hamburg, Bremen, and Lübeck. The only city-state extant today is Vatican City.

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