Analysis of Roman coinage sheds light on financial crisis

Metallurgical analysis of coins from the period revealed a significant decrease in the value of the denarius.

A study involving the scientific analysis of Roman coinage has revealed a significant debasement in the value of silver denarii at the start of the 1st century BC, shedding new light on a financial crisis alluded to by Roman statesman and writer Marcus Tullius Cicero in his essay on moral leadership, De Officiis.

Dr Matthew Ponting sampling a silver Roman coin. IMAGE: Professor Kevin Butcher, University of Warwick.

Metallurgical analysis of coins from the period revealed a significant decrease in the value of the denarius. Produced in pure silver before 90 BC, the coinage was being deliberately alloyed with up to 10% copper by 87 BC.

After fighting a war in Italy from 91 to 87 BC with its own autonomous allies, the Roman state was at risk of bankruptcy. These new findings suggest this financial strain led to a relaxation of minting standards which, as hinted to by Cicero, subsequently triggered a currency crisis.

‘Historians have long debated what the statesman and scholar meant when he wrote “the coinage was being tossed around, so that no one was able to know what he had.” (De Officiis, 3:80) and we believe we have now solved this puzzle,’ said Professor Kevin Butcher from the University of Warwick.

Dr Matthew Ponting from the University of Liverpool added that the ‘Romans had been used to an extremely fine silver coinage, so they may well have lost confidence in the denarius when it ceased to be pure.’

Copper drilled from beneath the silvery surface of a Late Hellenistic coin (not one of those involved in the study) demonstrating how debasement could be disguised. IMAGE: Professor Kevin Butcher, University of Warwick.

Cicero referred to the crisis in a moral anecdote describing the self-interest of the Roman praetor Marius Gratidianus, who claimed sole credit for a currency reform devised jointly by the tribunes and college of praetors.

Professor Butcher adds that around the time Gratidianus published his edict, the silver content of the denarius rose sharply, reversing the debasement and restoring it to a high-quality currency.

The discovery comes as part of a five-year project, ‘Rome and the Coinages of the Mediterranean 200 BCE – 64 CE’, funded by the European Research Council as a collaboration between researchers at the Universities of Warwick and Liverpool, the ISIS Neutron and Muon Facility, and the STFC Rutherford Appleton Laboratory.

By analysing the chemical composition of all major silver coinages in circulation during this period, the project aims to shed light on the financial strategies of Hellenistic and Classical Mediterranean states.