Marcus Tullius Cicero wrote an essay on moral leadership in 44 BC. This briefest of mentions fueled a longstanding historical debate, one that has just been answered by the coins themselves.

Historians have debated what the scholar meant when he said coinage was tossed around so no one could know what he had.

The Roman state teetered on the edge of financial ruin in the early 90s due to the Social War against their Italian allies who wanted citizenship along with the power to vote in Roman elections. Cicero said that people were losing confidence in their currency, the denarius, as Rome was in a debt crisis.

The god Bacchus is depicted in a Denarius coin. The University of Warwick.

Cicero said that the Roman tribunes approached the college of Praetors to resolve the crisis before Gratidianus claimed sole credit for the collective effort.

One theory is that Gratidianus fixed the exchange rate between the silver denarius and the bronze. He published a method for detecting fake denarii, which restored faith in the coinage.

Cicero's choice of words is too obscure for historians to determine what was going on. His purpose in writing about it was not to illuminate monetary history, but to show how a Roman magistrate behaved badly by taking credit for the work of others.

Butcher and colleagues analyzed the composition of the coins that were made during these years. They used minimally intrusive sampling techniques to prevent damaging the precious silver relics, which were first introduced as currency in 211 BCE, valued at ten bronze ass.

The denarius was composed of pure silver before 90 BCE, but it dropped 10 percent after that.

The denarius first dropped to 95 percent fine, and then it fell again to 90 percent, with some coins as low as 86 percent, suggesting a severe currency crisis.

A money exchanger in Rome. The Museum of Roman Civil is in Rome.

The state selling off public land to buy grain in 89 BCE is one of the evidence of financial troubles.

There was a huge increase in coin production in 90 BCE, with 2,372 dies and the molds to make the coins, compared to the previous year. Rome was struggling to finance the Social War.

During the civil war between Pompey and Julius Caesar, the Romans once again debased their currency, androme turned to further conquests and taxing citizens to ensure its financial stability. The coins that were produced in 87 BCE did not have the same level of debasement.

This could be the meaning of Cicero's words, that the value of the coinage was dependent on whether the denarii they had were pure or not.

The standard of fineness rose sharply around the time Gratidianus published his edict, reversing the debasement and restoring the denarius to a high-quality currency.