11. Unlike his wise father, Commodus was no economist, and his short-term fix of devaluing the Roman currency soon caused real trouble
As soon as he took sole control of the Empire in the year 180, Commodus got busy devaluing the Roman currency. At first, he reduced the weight of the denarius from 3.85 grams to 3.35 grams. At the same time, he also reduced the weight of silver coins by making them less pure. Just six years later, he further devalued both gold and silver coins, largely to make sure that he had enough of the precious metals to pay for his opulent lifestyle and to fund his habit of paying his legionaries regular bonuses to keep them loyal and onside.
This policy was far from wise. In fact, though it proved a short-term fix for Commodus, it caused significant damage to the Roman economy over the longer term. So much so, in fact, that the ancient observer Dio Cassius, who witnessed the economic debacle first-hand, described the way Commodus squandered his legacy. For him, the transition from Marcus Aurelius to his reckless son represented the start of the descent of the Empire “from a kingdom of gold to one of iron and rust” – though, of course, he didn’t dare criticize the Emperor’s economic policies to his face!