Ancient history

An analysis of the composition of Roman denarii sheds light on the financial crisis mentioned by Cicero

A new scientific analysis of the composition of Roman denarii has provided new insights into a financial crisis briefly mentioned by Roman statesman and writer Marcus Tullius Cicero in his essay on moral leadership, De Officiis , and has resolved an age-old debate.

Researchers from the University of Warwick and the University of Liverpool have analyzed coins from the period and revealed much greater coinage debasement than historians thought, with coins that had been pure silver before 90 BC. cut with up to 10% copper five years later.

Dr Ponting of the University of Liverpool said:The Romans were used to an extremely fine silver coin, so it is quite possible that they lost confidence in the denarius when it ceased to be pure. The exact level of debasement might have been less important to contemporaries than the mere realization that the coin was adulterated and no longer true "silver" .

Professor Butcher, from the University of Warwick, said:The discovery of this significant decline in the value of the denarius has shed new light on Cicero's hints of a currency crisis in 86 BC. Historians have long debated what did the statesman and scholar mean when he wrote that “the currency was turned around, so that no one could know what he had” (De Officiis, 3:80). We think we have now solved this puzzle .

The reference is part of an anecdote describing the self-serving behavior of Marco Mario Gratidiano, who took credit for a monetary reform proposal worked out jointly by the tribunes and the college of provosts and who, as a result, became enormously popular with the public.

But what was the cause of the currency being "scrambled", and what solutions did Gratidiano take credit for?

Rome and Mediterranean coins 200 B.C. – 64 AD ., a five-year research project funded by the ERC, aims to increase our understanding of the economies of classical Rome and other Mediterranean states by analyzing the composition of their coins and cross-referencing the results with historical records.

The research team consists of Professor Kevin Butcher, from the University of Warwick, Dr Matthew Ponting, from the University of Liverpool, and Dr Adrian Hillier, from the ISIS Neutron and Muon Facility , from the STFC Rutherford Appleton Laboratory .

Dr Ponting said:Our minimally invasive sampling technique used to sample these important coins has revealed a significant decline in the value of the denarius:from being a pure silver coin, the denarius first fell below 95% purity, and then fell back to 90%, with some coins as low as 86%, suggesting a serious currency crisis.

Professor Kevin Butcher explains the context:In the years after 91 B.C. the Roman state was in danger of bankruptcy. The Romans were at war with their own allies in Italy, and at the end of the war, in 89 BC, there was a debt crisis. In the year 86 B.C. it seems that there was also a crisis of confidence in the currency. Cicero recounted how Roman tribunes turned to the college of provosts to settle the crisis, before Gratidian took credit for the collective effort.

One theory is that Gratidianus fixed the exchange rate between the silver denarius and the bronze ace (whose weight had recently been reduced). Another is that he published a method to detect counterfeit denarii, thus restoring faith in the currency. Unfortunately, Cicero's choice of words is too obscure for historians to determine exactly what was going on. His purpose in writing about it was not to illuminate monetary history; he was just using the incident as an illustration of a Roman magistrate misbehaving by claiming the work of others .

It has long been thought that there was a very slight devaluation of the denarius between 89-87; but was it enough to trigger a currency crisis? The results of the metallurgical analysis suggest that the financial difficulties experienced by Rome in these years led to a relaxation of the rules at the mint in 90 BC, with the result that the silver content of the coin decreased in two stages, from so that in the year 87 B.C. the coin was deliberately alloyed with 5-10% copper.

Professor Butcher added:This could be the meaning of Cicero's words:that the value of the coin was 'scrambled' because no one could be sure whether the pence they had was pure or not . Even more noteworthy is the fact that, around the time Gratidian published his edict, the standard of fineness was raised sharply, reversing the debasement and restoring the denarius as a high quality coin .

Although the precise chronology remains uncertain, new scientific data suggests that it may have been the primary purpose of Gratidian's edict, rather than anything to do with silver/bronze exchange rates or detecting forgeries . In the following decades, the Romans avoided degrading the denarius again, until the state again faced great expense during the civil war between Pompey and Julius Caesar. Even then, the Roman mint did not go as far as it did in Gratidian's time.

These findings are part of a larger EU-funded study that aims to examine the financial and monetary strategies of Mediterranean states from c. 150 BC to a major coin minting reform around AD 64, providing a detailed and reliable set of analyzes of the chemical composition of all the major silver mintings of that period.