Capital cities that are also the prime economic, cultural, or intellectual centres of a nation or an empire are sometimes referred to as primate cities. Examples are Athens, Brussels, Buenos Aires, Cairo, London, Mexico City, Paris, Stockholm, Tokyo, and Warsaw.
News media will often use the name of a capital city as an alternative name for the country of which it is the capital or of the government that is seated there, as a form of metonymy. For example, "relations between Washington and London" refer to "relations between the United States and the United Kingdom".
In several English-speaking states, the terms county town and county seat are also used in lower subdivisions. In some unitary states, subnational capitals may be known as "administrative centres". The capital is often the largest city of its constituent, though not always.
Historically, the major economic centre of a state or region often becomes the focal point of political power, and becomes a capital through conquest or federation. (The modern capital city has, however, not always existed: in medieval Western Europe, an itinerant (wandering) government was common.) Examples are Ancient Babylon, Abbasid Baghdad, Ancient Athens, Rome, Constantinople, Chang'an, Ancient Cusco, Madrid, Paris, London, Moscow, Beijing, Tokyo, Vienna, Lisbon and Berlin. The capital city naturally attracts politically motivated people and those whose skills are needed for efficient administration of national or imperial governments, such as lawyers, political scientists, bankers, journalists, and public policy makers. Some of these cities are or were also religious centres, e.g. Constantinople (more than one religion), Rome (the Roman Catholic Church), Jerusalem (more than one religion), Ancient Babylon, Moscow (the Russian Orthodox Church), Belgrade (the Serbian Orthodox Church), Paris, and Peking.
The convergence of political and economic or cultural power is by no means universal. Traditional capitals may be economically eclipsed by provincial rivals, e.g. Nanking by Shanghai, Quebec City by Montreal, and numerous US state capitals. The decline of a dynasty or culture could also mean the extinction of its capital city, as occurred at Babylon and Cahokia.
Although many capitals are defined by constitution or legislation, many long-time capitals have no legal designation as such: for example Bern, Edinburgh, Lisbon, London, Paris, and Wellington. They are recognised as capitals as a matter of convention, and because all or almost all the country's central political institutions, such as government departments, supreme court, legislature, embassies, etc., are located in or near them.