Settlers, Sea Engineers, and Space Engineers can build a city or colony. After this, the Settler is removed and becomes the first citizen.
Great Library entry[]
Since the beginning of time man has pushed forward, crossing into hostile, lonely territory where he has settled, establishing a home, a family, a business: forming the seeds of a future city. In the early stages of Civilization as nomads learned to domesticate animals and cultivate the land, they spread across continents and formed cities. As cities grew, war, disease, and other events caused large populations to migrate from city to city causing even greater expansion, eventually into the oceans and space.