The Roman Empire has an emperor, and his name is Sponsianus. He reigned approximately from 260 to 270 in the province of Dacia (present-day Romania). British scientists say this after examining a gold coin with Sponsianus’ name and face on it. It was long assumed that the coin was a counterfeit, but after analyzing the composition of the metal, the traces of use and the encrusted earth, the researchers conclude that it is genuine.
The name of Sponsianus is known only from a collection of coins found in 1713 in Transylvania. In the eighteenth century that region was part of the Habsburg Empire, but in the middle of the third century the Romans ruled their province of Dacia here. This was a particularly troubled period, which has gone down in history as the ‘Crisis of the Third Century’. Emperors, counter-emperors and invading barbarians fought for power. Sometimes there were several emperors at the same time, in different places in the empire.
Because there is no mention of an emperor Sponsianus anywhere in written sources, experts assumed that the coin with his image was a forgery. Over time, the gem has moved from the Imperial collection in Vienna to the collection of the University of Glasgow. There, scientists from that university and University College London examined the coin – and three other coins from the same find from 1713 – with a regular microscope and an electron microscope, and with the help of infrared and UV light. They published their findings on Wednesday in the magazine PLOS ONE.
It is not surprising that until now it was assumed that the coin was a counterfeit. The counterfeiting of Roman coins started as early as the sixteenth century and quickly became more professional when it became apparent that there was a market for it. Counterfeiters used all sorts of tricks to make their creations look older.
The coin of Sponsianus was not minted, as was the case with regular Roman coins, but cast. This can be explained, the researchers write, because in the 260s Dacia was de facto cut off from Rome, where the official currency was located. Means of payment therefore had to be manufactured on site using the available technology.
The coin is also unusual because the emperor’s head bears his name in the genitive case: IMP SPONSIANI (of the emperor Sponsianus). And on the reverse, a coin design has been copied from the time of the Roman Republic – so from before the beginning of our era. The maker of the coin thought it read C AVG: CAESAR AVGVSTVS (a usual addition for an emperor), but this was the name Caius Augurinus, a mint master from the Republic.
A counterfeiter working for the collector’s market would not make such a mistake, the researchers concluded. Furthermore, the wear of the coin was a product of years of use and not of conscious treatment. The caked earth indicated a long stay underground. The composition of the gold, with a relatively high percentage of silver, is similar to other gold known to come from Dacia.
The authors therefore state that the coin is genuine and hypothesize that Sponsianus was an army commander proclaimed emperor in Dacia at a time when that province was cut off from the rest of the empire. He had to keep the barbarians out there. To pay his troops, he had coins made from local gold by an inexperienced craftsman. When Rome finally gave up on Dacia in the mid-270s, Sponsianus’ rule came to an end.