The great imperial or royal cities of the medieval Mediterranean world were, by their nature, active centres of commerce; in them all the different cultures of the maritime countries, and, often, of those from the ultramontane regions, or of countries beyond the deserts, met face to face. Thus, for example, flourished Cordova, Constantinople, and Palermo.

In Genoa, the consequences of the meetings of the different cultures were not dependent on political power, nor on the extent of empire, nor on the personality or vagaries of any particular sovereign. The town was not a great administrative centre, nor was it a centre of intellectual or religious activity. Although a beautiful town, well built in solid stone, and endowed with imposing palaces, Genoa was not even the centre of a particularly active artistic life. The cultures met because of the very nature of the city, its essential functions. Genoa is a merchants' city, open to distant cultures uniquely by virtue of trade.