įurther information: List of ancient Greek cities, List of Phoenician cities, Cities of the ancient Near East, Italian city-states, Maya city, Polis, and Altepetl Hong Kong, Macau, and members of the United Arab Emirates-most notably Dubai and Abu Dhabi-are often cited as such. Several non-sovereign cities enjoy a high degree of autonomy and are often confused for city-states. The Economist refers to the nation as the 'world's only fully functioning city-state'.

Out of these, Singapore is the largest and most populous, and is generally considered to be the last real city-state left in the world, with full sovereignty, international borders, its own currency, a robust military, and substantial international influence in its own right.

With the rise of nation states worldwide, there remains some disagreement on the number of modern city-states that still exist Singapore, Monaco and Vatican City are the candidates most commonly discussed. They have existed in many parts of the world since the dawn of history, including cities such as Rome, Carthage, Athens and Sparta and the Italian city-states during the Middle Ages and Renaissance, such as Florence, Venice, Genoa and Milan. A city-state is an independent sovereign city which serves as the center of political, economic, and cultural life over its contiguous territory.