In 1956, Carlo Cipolla, an Italian medievalist, published five short lectures under the title Money, Prices and Civilization in the Mediterranean World.

They’re interesting even if you don’t happen to be into medieval money. Cipolla, for example, dedicates a chapter to what he calls the dollars of the middle ages, the high-value gold florins and ducats of the Italian city states, accepted and copied from Constantinople to the Rhineland.

Kingdoms and cities, Cipolla points out, did not have what we now think of as monetary sovereignty — a monopoly on the issue and control of currency within their own borders. Coins, particularly the most valuable ones, moved promiscuously from private mints to any market they pleased, and the best a king or a doge could hope for was a way to regulate the mints and manage the flow of coins. Money, Prices and Civilization is accidentally the single-best explanation of how money works now, today, in our current economy.