A city is the major urban settlement of a region. It is part of specific factions in the games Rome: Total War, Medieval II: Total War, Empire: Total War and Napoleon: Total War. Cities are one of the key parts of the Total War series as it can create units and buildings. The urban areas also can manage trade, helping the economy of the specific country. Naturally, the population of a city gets larger; the city size must be upgraded or else the population will riot, causing deaths and damage to buildings.
Cities were introduced in the game Rome Total War. They played in the role of being region capitals; cities needed to be taken in order for the region to be taken. In previous games to capture a settlement you merely just had to be the faction with a army in that region.
In Empire: Total War and Napoleon: Total War cities again play the role of region capitals however lose some of their abilities to construct certain buildings with the introduction of towns.