Whereas the nation-states rely on a common cultural heritage, be it linguistic, historical, religious, economic, etc., the city-state relies on the common interest in the function of the urban center. The urban center and its activity supplies the livelihoods of all urbanites inhabiting the city-state.
Several sovereign countries do have self-governing areas delineated around cities, but these are not true city-states because they are not independent of the larger state. Typically a federal country will have a federal administration from which the capital is granted a separate status. Examples include Washington, D.C. in the United States, Brasília (coterminous with the Brazilian Federal District) in Brazil, Mexico City (being the Mexican Federal District), Canberra (part of the Australian Capital Territory) and Ciudad Autónoma de Buenos Aires (coterminous with the Argentine Federal Capital).
In nations without a federal administrative structure, capital cities sometimes enjoy a greater degree of autonomy, e.g. London. In Germany, Berlin has been a federal state (Land) of its own since 1990, but, unlike the above, remains inside the general administration of the country. (Note but this has nothing to do with its being the capital; the cities of Hamburg and Bremen have an identical status and look back on a much longer history of political independence.) A similar situation can be found in Austria, where the capital Vienna has the status of a state within the Austrian federation of states.
Yet another case is the Special Administrative Regions of the People's Republic of China; Hong Kong and Macau. Neither capitals nor exclusively cities, their temporary, relative political independence results from agreements between China and the colonial powers that formerly controlled them.
However, city-state cultures were far from universal in the ancient world. In some regions, such as the ancient Andes, large territorial states, empires, and other forms of polity were common but city-state cultures did not develop. Archaeologist Bruce Trigger identified city-states as one of two basic forms of political organization among ancient civilizations; the other form being the large territorial state.
There were essentially three classes of states. The majority were probably ruled by petty chiefs (known as lugal in the ancient Middle East, wanax in the Mycenean world, and kshatriya in India). The Book of Joshua also makes reference to "kings" of several dozen cities occupied by the invading Israelites, although their powers are not specified. A second class of cities formed part of much larger political entities whom they served either as capitals or as provincial centers. The third type comprises self-governing cities.
Examples of city-states and city-state cultures include:
During the long history of the Holy Roman Empire, dozens of towns and cities obtained local independence. By the late 18th century, their number had slowly been reduced to around 50, but almost all were incorporated into larger polities during the German Mediatization in 1803. By 1815, once peace had returned at the end of the Napoleonic era, only Bremen, Hamburg, Lübeck and Frankfurt remained independent. Those four cities became members of the German Confederation (effectively the Holy Roman Empire's successor). Frankfurt was annexed by Prussia in 1866, while Lübeck, Hamburg and Bremen joined the North German Confederation in 1867, which was later incorporated into the German Empire. Hamburg and Bremen have continued until today as states in the modern Federal Republic of Germany, while Lübeck lost its independence in 1937 by the Greater Hamburg Act.
This was exemplified in the Amsterdam Town Hall erected at the time on the Dam Square, which was sumptuous enough to be later converted into a Royal Palace (which it still is), and having among its decorations a giant painting of Imperial Amsterdam depicted as an enthroned Queen, served by three female slaves representing Asia, Africa and America.
San Marino, the third smallest state in Europe, is an independent enclave surrounded by Italy. The capital, and center of government, is the City of San Marino, located on the western slopes of Monte Titano. Geographically, the entire country is approximately the size of Syracuse, New York.
San Marino is the oldest constitutional republic in the world, having been founded on 3 September 301 by Marinus of Rab, a Christian stonemason fleeing the religious persecution of Roman Emperor Diocletian. San Marino's constitution, dating back to 1600, is the world's oldest written constitution still in effect.
Prior to the 19th century, Singapore was a minor part of various regional empires, including Srivijaya, Majapahit, Malacca and Johor. From 1826 to the Japanese conquest, Singapore was the capital of the Straits Settlements, a British colony that included the Settlements of Malacca and Penang along the Straits of Malacca. After the Second World War, Singapore was hived off as a separate colony while the other two Settlements joined the Malay States to form the Federation of Malaya. In 1963, Singapore merged with Malaya, Sabah and Sarawak to form Malaysia. However, due to a number of problems, Singapore left the federation in 1965, becoming an independent republic.
Since 1965, Singapore rapidly industrialised and modernised, becoming one of the four "Asian Tigers". In addition to the substantial absolute and per-capita size of its economy, Singapore maintains a significant armed force. It ranks highly in terms of defence spending and troop size. Singapore may be a small country, but it is a medium to large sized developed city. Despite its small land area, Singapore has a population, economy and armed forces that place it in a similar league to small but full fledged nations like New Zealand, Ireland, Israel and the Nordic countries, rather than semi-dependent microstates. Singapore also maintains diplomatic representation around the world, including membership of international organizations like the UN, the Commonwealth and ASEAN. Singapore places emphasis on self-sufficiency in basic needs, like water. The government also stockpiles other key resources, such as sand and oil. In this way, Singapore tries to avoid overdependence economically, politically or militarily on larger entities. As such, Singapore may represent the most complete contemporary example of a city-state, meeting the full definitions of both a city and a fully sovereign state.
The impasse was resolved in 1929 by the Lateran Treaties negotiated by the Italian dictator Benito Mussolini between King Victor Emmanuel III and Pope Pius XI. Under this treaty, the Vatican was recognized as an independent state, with the pope as its head. The Vatican City State has its own citizenship, diplomatic corps, flag, and postal system. With a population of less than 1000, it is by far the smallest sovereign country in the world, and widely recognized internationally as such.
It is administered by the City of London Corporation, headed by the Lord Mayor of the City of London (not the same post as the more recent Mayor of London, who presides over Greater London). The City is a ceremonial county too, although instead of having its own Lord-Lieutenant, the City of London has a Commission, headed by the Lord Mayor, exercising this function.
Not being part of any U.S. state, Washington, D.C.'s government operates under authority derived from the U.S. federal government. The city is run by an elected mayor (currently Adrian Fenty) and a city council. The council is composed of 13 members: one elected from each of the eight wards and five members, including the chairman, elected at large. The council conducts its work through standing committees and special committees established as needed. District schools are administered by a chancellor, who is appointed by the mayor; in addition, a Superintendent of Education and a Board of Education are responsible for setting some educational policies. There are 37 elected Advisory Neighborhood Commissions that provide the most direct access for residents to their local government. The commissions are elected by small neighborhood districts, and their suggestions are given "great weight" by the D.C. Council and city agencies. However, the U.S. Congress has the ultimate plenary power over the District. It has the right to review and overrule laws created locally and has often done so. The Tenth Amendment to the United States Constitution, which grants to states all rights not belonging to the federal government, does not apply to the District of Columbia. Residents of the District of Columbia do not have voting representation in Congress.
Countries that have a very high proportion of their population within a single city, such as Kuwait and Djibouti, are sometimes referred to as virtual or near city-states, especially when they are relatively small in total land area; however, city-states are not small nation-states. Likewise, cities with their own quasi-sovereign states in larger nations or federations, like Dubai in the United Arab Emirates, do not technically qualify as city-states.