Long dismissed as fakes, handful of ancient Roman coins unearthed in Transylvania more than three centuries ago have been validated by new analysis.
It is not difficult to see why the coins – dating to the 260s AD – they might have been considered fake. Where most ancient coins feature the head of an emperor, one of the artifacts features a mysterious figure not depicted in any other known record.
On some the name “Sponsian” is stamped, a form the Roman history of power seems to have forgotten.
“Scientific analysis of these extremely rare coins rescues the Sponsian emperor from obscurity,” says University College London earth scientist Paul Pearson, who led the study.
Discovered in 1713, the gold aurei coins had been labeled poor forgeries in the mid-19th century by the leading expert of the time, a man named Henry Cohen, due to several irregularities. They differ in construction and style from the authentic coins of their period, for example, they vary greatly in weight, have mixed patterns and jumbled inscriptions.
Imitations of Roman coins were made outside the empire at that time, and again during the Renaissance period as clearly fake trinkets. Later, more realistic fakes with simulated wear were made to fool wealthy coin collectors.
The weight of gold in the 1713 collection exceeds US$20,000 in modern value. Three of the four coins held at the Hunterian Museum in Scotland over the past two centuries depict actual emperors, including one known as Philip the Arab, but the fourth features the mystery man.
The name Sponsian is also very curious, with the only other known example of it being from a Roman funerary inscription ‘Nicodemus Sponsian’ dating to the first century. Moreover, this unique other example of the name was not even known at the time of the discovery of the coins.
“Here we emphasize the fact that the inscription was excavated in the 1720s, so it could not have been known to a hypothetical forger, who would therefore have to have invented a peculiar name that later turned out to be genuine,” the team explains in their paper.
Using ultraviolet imaging, visible light and scanning electron microscopy, Pearson and his colleagues found scratches covering the surfaces of the coins. This suggests that the tokens had experienced extensive use and circulation among other coins and had not been deliberately scratched to mimic usage. Small pieces of soil cemented to the surfaces support the claim that the artifacts were actually buried for a long time.
The coins have a variety of compositions, all over 90 percent gold but also with varying small admixtures of silver and copper. This differs from two genuine Roman mint coins used for comparison, which are essentially pure gold.
The Sponsian coin, in particular, has a distinct mixture of gold, silver, and copper unlike the proportions measured in any of the other coins. While this may indicate that the coins are modern forgeries, Pearson and colleagues conclude that it probably means that the coins were minted outside of ancient Rome, “probably made from imperfectly refined ore.”
Historians have previously speculated that Sponsian may have been a brief usurper during the reign of Philip the Arab in the 240s. But the fact that Philip appears on some of the coins in the same collection contradicts the idea that Sponsian usurped him, the researchers argue.
“These observations compel a reassessment of Sponsian as a historical figure,” Pearson and team write. “We suggest that he was probably an army commander in the isolated Roman province of Dacia during the military crisis of AD 260.”
So while he may not have ruled all of Rome, Sponsian seems to have carved out his own small empire in a remote gold-mining outpost, with a crude coinage using metals from local mines, probably after the start of the Roman Empire. researchers suspect.
“We suggest that Dacia was cut off from the imperial center around 260 [CE] and effectively seceded under its own military regime, which first coined bullion bars using old Republican-era designs, then using the names of more recent previous emperors who had achieved some success in the region, and finally with the name of a local commander – leader,” explains the group.
Sponsian crude coinage supported a functional monetary economy that was sustained locally for a considerable period.
This would explain why the Sponsian never appeared in any official Roman records, as well as the oddity of the coins.
“The evidence shows us [Sponsian] he ruled Roman Dacia … at a time when the empire was wracked by civil wars and the frontiers were overrun by marauding raiders,” Pearson concludes.
This research was published in PLOS ONE.