Debasement of Roman Silver Coinage

By: Jonah Scoles

This article is about the debasement of Roman coinage from the middle of the 1st century through the fall of the Roman Empire. Debasement is when the intrinsic value of a coin is reduced by using less of a precious metal to mint it. To understand how far these coins were debased we must first understand what these coins were like beforehand.

In the early 1st century, Roman silver coins, particularly the denarius, contained approximately 95% silver. This would not last. Towards the middle of the 1st century, Emperor Nero began the debasement of the precious metals in his coins to an average of 93% silver. Even though it was not really a noticeable amount it started a trend of debasement among later emperors.

In the middle of the 2nd century, during the reign of Hadrian, the amount of silver in coins had been reduced to approximately 90%. This debasement of Roman coins allowed emperors to spend less silver on the production of coins. Again, even though it was not a large reduction in silver content, it does show that the debasement of Roman coins was a trend.

In the early 3rd century, among other changes, Caracalla altered the monetary system to include the antoninianus. The antoninianus was a silver coin comprised of approximately 60% silver and weighed about five grams (approximately 1.5 denarii by weight) but had a value equal to two denarii.

In the middle of the 3rd century, the denarius was nearing its end due to the monetary reform of Diocletian, which introduced the argentium, among order to keep its silver appearance, the antoninianus was treated with acid that removed the base metals from the coin. This left a porous, almost spongy silver layer on top giving the coin a silver appearance even though there was not much silver left in it.

As inflation and the inevitable debasement of these coins rose, Roman coins subsequently became less valuable. The debasement of these coins reached a point where they were being silver plated and had a mere 2% of silver still left in them.

At the beginning of the 4th century, the denarius was so debased that there was no silver left in it. It was being minted in only bronze and copper before being abandoned shortly after. Later in the 4th century, Constantine the Great instituted the siliqua and the miliarense. Both coins contained low silver content, topping out around 20%. Like the antoninianus, the siliqua and miliarense were most likely treated in an acid that removed the base metals from the surface giving them a silvery appearance.

The problem with this method of treating them in acid was that the silver layer on the surface wore away very fast leaving the copper or brass exposed. Coins that still have this silvering on the surface are rarer and are worth more than those without it. But because these coins are relatively common in the first place, they can still be collected with relative ease.

Debasement occurred to produce coins more cheaply. I believe this was largely due to the Roman Empire having more military campaigns than the Roman Republic. Military campaigns are expensive. As a result, the Empire chose to debase their coins as a short-term fix to their money problems. This short-term fix became a pattern that eventually resulted in high value coins being minted from bronze and copper rather than their higher valued silver counterparts.

Thank you, Jonah, for an excellent article!!!