Inflation in ancient Rome

Quantitative easing in ancient Rome
It would seem clear that the major single cause of the inflation was the drastic increase in the money supply owing to the devaluation or debasement of the coinage. In the late republic and early empire, the standard Roman coin was the silver denarius; the value of that coin had gradually been reduced until, in the years before Diocletian, emperors were issuing tin-plated copper coins that were still called by the name "denarius." Gresham's law, of course, became operative; silver and gold coins were naturally hoarded and were no longer found in circulation.

During the fifty-year interval ending with the rule of Claudius Victorinus in A.D. 268, the silver content of the Roman coin fell to one five-thousandth of its original level. With the monetary system in total disarray, the trade that had been hallmark of the empire was reduced to barter, and economic activity was stymied.