In EU2, a city is a type of settlement which has a population of at least 1000. All kinds of city upgrades and military units may be constructed in a city, as long as the province and its owning country fulfill each item's prerequisites.
Colonial Cities[]
Cities with population between 1000 and 4999 (inclusive) are called colonial cities. In general colonial cities work just like larger cities, however, there are a few rule variations, especially when a colonial city is on a different continent than the capital of its country.
Full Cities[]
When it is important to distinguish cities with population of 5000+ from colonial cities, they may be called "full cities". This is not a widespread usage.
Creation of New Cities[]
There is only one way in which new cities are created in EU2: colonization. Colonies become cities when their population reaches 1000. If natives are present, they will join the colony when it reaches 900 population, which will make it a city.
There is no way to destroy a city, nor demote it to a colony. A city cannot be reduced below 1000 population by any means.
Initial Cities[]
In the vanilla 1419 grand campaign, most provinces in Europe, Asia, and North Africa begin the game as cities. Exceptions in Europe are colonies in the Azores, the Canaries, Iceland and some provinces in northern Scandinavia and Russia. In Asia, most of Siberia is uncolonized, as are several provinces on the coast of India. Additionally there are 5 colonies owned by Indian minors on the the south Indian coast that are always destroyed by natives.
Cities are also found at the beginning of the 1419 scenario in: Eastern North America, central and southern Mexico, inland areas in the American Southwest, the western coast of South America, in West Africa, and intermittently along the coast of East Africa. All cities and countries in America and southern Africa are pagan.