Nick Szabo looks at the history of Genoa, “the most commercially innovative city of premodern times”:
Insurance, the joint-stock corporation, close cooperation between navy and merchant marine, international trade and exploration, and banking all made substantial progress in Genoa. The basic drivers of these innovations were Genoa’s merchant culture and its unprecedented commitment to freedom of contract.
The Genovese struggled against Church doctrine banning usury by hiding interest charges as profits or exchange rates:
An example of the use of exchange rates to incorporate interest was the “dry loan” which structured interest as a transport charge commonly used in a “wet loan” which were normally paid off in a distant city as a way of transmitting money. Church leaders recognized many of these ruses and complained, but since Genovese municipal judges were, like the rest of the Genovese community, staunch advocates of freedom of contract, and since the Church was dependent on Genovese power (for example to transport and protect crusaders and pilgrims on the seas), the judges winked at these ruses and the Church mostly did not crack down on the practice. In the process of developing these ruses the Genovese became creative drafters of commercial contracts and learned to distinguish elements such as risk, loan, and investment that had been bundled together and treated as inseparable in previous eras.