Vatican City in the context of "Tuvalu"

A city-state is an independent sovereign city which serves as the center of political, economic, and cultural life over its contiguous territory, as opposed to a regular state or country comprising a capital city and other cities and/or a countryside. City-states have existed in many parts of the world throughout 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.

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. Out of these, Singapore is the largest and most populous city-state in the world, with full sovereignty, international borders, its own currency, a robust military, and substantial international influence in its own right. The Economist refers to it as the "world's only fully functioning city-state".

A microstate or ministate is a sovereign state having a very small population or land area, usually both. However, the meanings of "state" and "very small" are not well-defined in international law. Some recent attempts to define microstates have focused on identifying qualitative features that are linked to their size and population, such as partial delegation of their sovereignty to larger states, such as for international defense.

Commonly accepted examples of microstates include five historic European microstates: Andorra, Liechtenstein, Monaco, San Marino, and Vatican City. Malta and Luxembourg are sometimes included in that list but are generally considered too populous to be genuine microstates. Other examples are small, isolated island states in the Pacific Ocean: Nauru, Palau, Niue, Cook Islands and Tuvalu. Some small Caribbean countries such as Saint Kitts and Nevis, Barbados, Antigua and Barbuda, Grenada, Saint Vincent and the Grenadines may be considered microstates by some but are often not included due to them being grouped together as small island countries. Singapore and Bahrain are sometimes considered microstates but some argue are too populous, self reliant or powerful to be considered true microstates and their island status can play an important factor too.The smallest political entity recognized as a sovereign state is Vatican City, with fewer than 1,000 residents and an area of only 49 hectares (120 acres). Some microstates – such as Singapore, Monaco and Vatican City – are city-states consisting of a single municipality.

Rome is the capital city and most populated comune (municipality) of Italy. It is also the administrative centre of the Lazio region and of the Metropolitan City of Rome. A special comune named Roma Capitale with 2,746,984 residents in 1,287.36 km (497.1 sq mi), Rome is the third most populous city in the European Union by population within city limits. The Metropolitan City of Rome Capital, with a population of 4,223,885 residents, is the most populous metropolitan city in Italy. Its metropolitan area is the third-most populous within Italy. Rome is located in the central-western portion of the Italian Peninsula, within Lazio (Latium), along the shores of the Tiber Valley. Vatican City (the smallest country in the world and headquarters of the worldwide Catholic Church under the governance of the Holy See) is an independent country inside the city boundaries of Rome, the only existing example of a country within a city. Rome is often referred to as the City of Seven Hills due to its geography, and also as the "Eternal City". Rome is generally considered to be one of the cradles of Western civilization and Western Christian culture, and the centre of the Catholic Church.

Rome's history spans 28 centuries. While Roman mythology dates the founding of Rome at around 753 BC, the site has been inhabited for much longer, making it a major human settlement for over three millennia and one of the oldest continuously occupied cities in Europe. The city's early population originated from a mix of Latins, Etruscans, and Sabines. Eventually, the city successively became the capital of the Roman Kingdom, the Roman Republic and the Roman Empire, and is regarded by many as the first-ever Imperial city and metropolis. It was first called The Eternal City (Latin: Urbs Aeterna; Italian: La Città Eterna) by the Roman poet Tibullus in the 1st century BC, and the expression was also taken up by Ovid, Virgil, and Livy. Rome is also called Caput Mundi (Capital of the World).

The Tiber (/ˈtaɪbər/ TY-bər; Italian: Tevere [ˈteːvere]; Latin: Tiberis) is the third-longest river in Italy and the longest in Central Italy, rising in the Apennine Mountains in Emilia-Romagna and flowing 406 km (252 mi) through Tuscany, Umbria, and Lazio, where it is joined by the River Aniene, to the Tyrrhenian Sea, between Ostia and Fiumicino. It drains a basin estimated at 17,375 km (6,709 sq mi). The river has achieved lasting fame as the main watercourse of the city of Rome, which was founded on its eastern banks.

The river rises at Mount Fumaiolo in Central Italy and flows in a generally southerly direction past Perugia and Rome to meet the sea at Ostia. The Tiber has advanced significantly at its mouth, by about 3 km (2 mi), since Roman times, leaving the ancient port of Ostia Antica 6 kilometres (4 miles) inland. However, it does not form a proportional delta, owing to a strong north-flowing sea current close to the shore, due to the steep shelving of the coast, and to slow tectonic subsidence.

The Italian Peninsula (Italian: penisola italica or penisola italiana) is located within the Italian geographical region; it extends from the southern Alps in the north to the central Mediterranean Sea in the south which comprises much of the country of Italy and the enclaved microstates of San Marino and Vatican City.The peninsula is also known as the Italic Peninsula, Apennine Peninsula, Italian Boot, or Mainland Italy.

Italy, officially the Italian Republic, is a country in Southern and Western Europe. It consists of a peninsula that extends into the Mediterranean Sea, with the Alps on its northern land border, as well as nearly 800 islands, notably Sicily and Sardinia. Italy shares land borders with France to the west; Switzerland and Austria to the north; Slovenia to the east; and the two enclaves of Vatican City and San Marino. It is the tenth-largest country in Europe by area, covering 301,340 km (116,350 sq mi), and the third-most populous member state of the European Union, with nearly 59 million inhabitants. Italy's capital and largest city is Rome; other major cities include Milan, Naples, Turin, Palermo, Bologna, Florence, Genoa, and Venice.

The history of Italy goes back to numerous Italic peoples – notably including the ancient Romans, who conquered the Mediterranean world during the Roman Republic and ruled it for centuries during the Roman Empire. With the spread of Christianity, Rome became the seat of the Catholic Church and the Papacy. Barbarian invasions and other factors led to the decline and fall of the Western Roman Empire between late antiquity and the Early Middle Ages. By the 11th century, Italian city-states and maritime republics expanded, bringing renewed prosperity through commerce and laying the groundwork for modern capitalism. The Italian Renaissance flourished during the 15th and 16th centuries and spread to the rest of Europe. Italian explorers discovered new routes to the Far East and the New World, contributing significantly to the Age of Discovery.

Southern Europe is also known as Mediterranean Europe, as its geography is marked by the Mediterranean Sea. Definitions of southern Europe include some or all of these countries and regions: Albania, Andorra, Bosnia and Herzegovina, Bulgaria, Croatia, Cyprus, Gibraltar, Greece, Italy, Kosovo, Malta, Monaco, Montenegro, North Macedonia, Portugal, San Marino, Serbia, Slovenia, southern France, southern Romania, Spain, Ticino (Switzerland), Turkey, and Vatican City.

Southern Europe is focused on the three peninsulas located in the extreme south of the European continent. These are the Iberian Peninsula, the Italian Peninsula, and the Balkan Peninsula. These three peninsulas are separated from the rest of Europe by towering mountain ranges, respectively by the Pyrenees, the Alps and the Balkan Mountains. The location of these peninsulas in the heart of the Mediterranean Sea, as well as their mountainous reliefs, provide them with very different types of climates (mainly subtropical Mediterranean) from the rest of the continent. So, the Sirocco hot wind that originates in the heart of the Sahara blows over Italy, going up to the interior of the Alpine arc (Po Valley). The Alps prevent the Sirocco from spreading to the rest of Europe. And, conversely, the Alps and the Pyrenees protect the Italian and Iberian Peninsulas from the rains and icy winds from the south of France such as the Mistral and the Tramontane. When the Mistral and the Tramontane are blowing, this provokes an "upwelling" phenomenon on the French coast. They push the surface waters out to sea and bring deeper, cooler waters up to the seaside. Consequently, the temperature of the waters of the French coasts are therefore very cool even in summer, and not representative of the rest of the Mediterranean.This same kind of phenomenon takes place between the two slopes of the Balkan mountain range. These mountains have, moreover, been a serious handicap to population displacement, focusing southern Europe mainly on the Mediterranean world. The climate and cultures are therefore very specific.

Monaco, officially the Principality of Monaco, is a sovereign city-state and microstate in Western Europe. Situated on the French Riviera, it is a semi-enclave bordered by France to the north, east, and west, with the Mediterranean Sea to the south; the Italian region of Liguria is about 15 km (9.3 mi) east. With a population of 38,423 living in an area of 2.08 km (0.80 sq mi), Monaco is the second smallest sovereign state in the world, after Vatican City, as well as the most densely populated. It also has the world's shortest national coastline of any non-landlocked nation, at 3.83 km (2.38 mi). Fewer than 10,000 of its residents are Monégasque nationals. While the official language of Monaco is French, Italian and Monégasque are also widely spoken and understood.

Monaco is governed under a form of semi-constitutional monarchy, with Prince Albert II as head of state, who holds substantial political powers. The prime minister, who is the head of government, can be either a Monégasque or French citizen; the monarch consults with the Government of France before an appointment. Key members of the judiciary are detached French magistrates. The House of Grimaldi has ruled Monaco, with brief interruptions, since 1297. The state's sovereignty was officially recognised by the Franco-Monégasque Treaty of 1861, with Monaco becoming a full United Nations voting member in 1993. Despite Monaco's independence and separate foreign policy, its defence is the responsibility of France, notwithstanding two small military units.