The Roman monetary system was historically unique. Its complexity arose out of several intersecting and sometimes contradictory embedding contexts. This chapter identifies several important embedding contexts and provides a broad diachronic outline of their influence in the development of Roman money. Some of Rome’s Republican-era experiments with coinage, for example, were inescapably influenced by Greek practices and concepts. Roman territorial expansion seems to have been correlated with the rise of impersonal exchange in Rome, Italy and beyond – presenting unique cultural challenges for Roman elites in the Republican period. Notions of monetary value in the Roman Principate remained tethered to historical monetary contexts – but shifts in value and in the prominence of certain contexts over others could and did happen. Oscillations in the intensity and breadth of state power, for example, influenced money use, value and the scope for market exchange. It is impossible to import modern economic theory into Roman monetary history without first accounting for some of the key embedding contexts which shaped monetary practices, processes and concepts in the Roman world.

Gresham’s law is much more than the idea that ‘bad money drives out good’ always and everywhere. Instead, historians should use Gresham’s law as a complex and interconnected set of conditions and premises involving ‘external’ elements (legal tender laws, differing coinage standards, transaction costs etc.) and an ‘internal’ sensitivity among (some!) coin-users to the precious metal content of coins.The ‘external’ conditions of Gresham’s law seem to have been inconsistently present at best. Legal coin values and precious metal values were more or less redundant during first century and a half of the Principate. A growing dissonance between legal value and metal value, however, emerged by the late second century AD, putting pressure on coin-users’ monetary habits. The actions of Roman authorities encouraged any metallist-minded coin-users to avoid the now relative high costs of monetary exchange at legal values and instead adopt special-purpose uses for money. The counterfactual logic of Gresham’s law, therefore, offers historians both improved understanding of Roman coin-users’ thinking as well as broader insights into the workings of the Roman monetary economy.

The assumptions built into the quantity theory of money severely limit its usefulness for studying the Roman monetary system if not all pre-industrial monetary systems. Quantity theory fails to account for the complexity and disaggregated nature of the Roman monetary economy. This chapter, instead, disaggregates the workings of the monetary system by considering both money quantity and quality, the spatial and temporal properties of money and, finally, money’s value as a product of the subjective preferences of individuals. Instead of assuming money is neutral, Roman economic historians can and should examine the specific channels through which money entered the Roman economy. Depending upon the location of these channels in the larger political, cultural and social matrix, as well as the amount of money distributed through them, it may be possible to understand the human responses to money supply changes in the Roman world as well as the wider effects of these changes – effects which include not only price movements and the shifts in the structure of production but also realignments in social hierarchies.