Financial difficulties entered. The precious metals were running low: the gold mines of Thrace and the silver mines of Spain had reduced their yield, and Dacia, with its gold, would soon be surrendered by Aurelian. Much gold and silver had been consumed in art and ornament. Faced with this dearth when war was almost continuous, the emperors from Septimius Severus onward repeatedly debased the currency to pay for state expenses and military supplies. Under Nero the alloy in the denarius was ten per cent, under Commodus thirty, under Septimius fifty. Caracalla replaced it with the antoniniamus, containing fifty per cent silver; by 260 its silver content had sunk to five per cent. The government mints issued unprecedented quantities of cheap coin; in many instances the state compelled the acceptance of these at their face value instead of their actual worth, while it insisted that taxes should be paid in goods or gold. Prices rose rapidly; in Palestine they increased one thousand per cent between the first and third centuries; in Egypt inflation ran out of control, so that a measure of wheat that had cost eight drachmas in the first century cost 120,000 drachmas at the end of the third. Other provinces suffered much less; but in most of them inflation ruined a large part of the middle class, nullified trust funds and charitable foundations, rendered all business discouragingly precarious, and destroyed a considerable portion of the trading and investment capital upon which the economic life of the Empire depended.

The emperors after Pertinax were not displeased by this attrition of the aristocracy and the bourgeoisie. They felt the hostility of the Senatorial class and the great merchants to their alien origin, their martial despotism, and their exactions; the war of Senate and emperor, interrupted from Nerva to Aurelius, was renewed; and by donatives, public works, and doles, the rulers deliberately based their powers upon the favor of the army, the proletariat, and the peasantry.