textabstractCities are the focal points of the world economy. This paper sheds new empirical light on their origins. Using a new dataset covering over 250,000 randomly selected potential city locations, and all actual cities during the period 800–1800, we disentangle the different roles of geography in shaping today's European city system. We find that a location's physical geography characteristics are the dominant determinants of its urban chances. Preferential location for water- or land-based transportation is a particularly important city seed. In addition, a location's position relative to already-existing cities matters for its urban chances. Interestingly, it does so in a way corresponding to predictions from economic geography theo...