“The Romans had been used to extremely fine silver coins, so they may have lost faith in the denarius when it ceased to be pure,” said Matthew Ponting, one of the archaeologists involved in the research, in a press release. “The precise level of debasement might have been less important to contemporaries than the mere realization that the coin was forged and no longer genuine ‘silver’.”
Pointing explained that by using a minimally invasive sampling technique to take samples of significant coins, he and his colleagues were able to identify a significant drop in the value of the denarius – from being a pure silver coin, the denarius is first fell to less than 95% fine, then fell back to 90%, with some parts as low as 86%. This would suggest a serious monetary crisis.
In the words of Cicero
For the group, the discovery of this significant decrease in the value of the denarius brings some clarity to the quote from Cicero in 86 BC.
The reference is part of an anecdote describing the selfish behavior of Marius Gratidianus, who took credit for a monetary reform proposal worked out jointly by the tribunes and the college of praetors and thus became extremely popular with the public.
“In the years after 91 BC. J.-C., the Roman State was in danger of going bankrupt. The Romans were at war with their own allies in Italy, and when the war ended in 89 BC. AD, there was a debt crisis,” said researcher Kevin Butcher. “In 86 BC. J.-C., there also seems to have been a crisis of confidence in the currency. Cicero recounted how the Roman tribunes approached the college of praetors to resolve the crisis before Gratidianus claimed credit for the collective effort.
Butcher pointed out that one theory is that Gratidianus fixed the exchange rate between the silver denarius and bronze, the weight of which had only recently been reduced. Another proposal indicates that he published a method to detect counterfeit denarii and thus restore confidence in the currency.
“Unfortunately, Cicero’s choice of words is too obscure for historians to determine exactly what was going on,” the expert said. “His purpose in writing about this was not to illuminate monetary history; he was simply using the incident as an illustration of a Roman magistrate misbehaving by taking credit for the work of others.
The silver content decreased in two stages
The results of the metallurgical analysis suggest that the financial difficulties encountered by Rome during these years led to a relaxation of standards at the mint in 90 BC, with the result that the silver content of the mint fell in two steps so that by 87 BC the coinage was deliberately alloyed with 5-10% copper.
“That might be the meaning of Cicero’s words: that the value of money was ‘tossed about’ because no one could be certain whether the denarii they had were pure or not,” Butcher said. “It is all the more remarkable that at the time Gratidianus issued his edict, the level of fineness rose sharply, reversing the debasement and restoring the denarius to a high quality coinage.”
For the archaeologist, although the precise chronology remains uncertain, the new scientific data suggests that this could have been the main objective of the edict of Gratidianus, rather than something to do with the exchange rates between silver and bronze or forgery detection.
In the decades that followed, the Romans avoided degrading the denarius again, until the state again faced huge expenses during the civil war between Pompey and Julius Caesar. Even then, Roman coinage did not go as far as it had during the time of Gratidianus.