This chapter identifies a model of homogeneous development for all major port cities within the European economy during the period under examination, starting from the case of Genoa. The historiography of Genoa and its port and traffic between the late Middle Ages and the early modern era, though quite extensive, is mostly somewhat outdated, and only a very small part is available in English. Genoa was the capital city of one of the oldest regional states in the Ancien Regime. Genoa lies at the centre of the Ligurian Gulf overlooking the north Tyrrhenian Sea, and stretches along a natural arch bordered by two non-navigable rivers, the Bisagno and Polcevera. Valuable information on the composition of the Genoa-based merchant class can be obtained from a recent work by Van Doosselaere, who has examined and classified 20,000 notarial deeds for the period from 1150 to 1435.