- sovereign state consisting of a single city and its immediate surroundings
- historical city-states: Athens, Sparta, Corinth (ancient Greece), Venice, Florence, Genoa (Renaissance Italy), Carthage, Tyre (ancient Mediterranean)
- modern city-states: Singapore, Monaco, Vatican City, historically Hong Kong
- advantages: compact governance, rapid decision-making, high density of talent and capital, strong identity
- Athens: birthplace of democracy, direct citizen participation in assembly
- Venice: oligarchic republic lasting 1,100 years (697-1797), maritime trade empire governed by the Doge and Council of Ten
- Singapore: from colonial port to first-world economy in one generation, technocratic governance
- network state as the digital evolution of the city-state: concentrated community, global footprint, eventual physical territory
- cyberia carries the city-state pattern: a defined territory governed by protocol, dense enough for collective intelligence
- cyber valley as the physical seed of a cyber city-state
- see also sovereignty, federation, empire, startup societies