Roman coins, AR Denarius, Antoninus Pius 138 b.c., Rome.

The Roman Republic began its rise to mastery of the Mediterranean in a series of brutal and drawn-out wars with rival Carthage.

A new analysis of the metal content of Roman coins shows the crucial turning point to world dominance, according to a team of German archaeologists. 

“What our work shows is that the defeat of Hannibal and the rise of Rome is written in the coins of the Roman Empire,” said Katrin Westner, one of the scientists, of Goethe University in Frankfurt.

The evidence is in the lead isotopes of Roman coins, they say: the 208Pb, 207Pb, 206Pb, and 204Pb all show a change after the result of the victory over Hannibal’s legendary forces.

Mass spectrometry was used to show the lead in coins over a period of more than two centuries.

The 70 Roman coins dated from 310 B.C. to 101 B.C., they report, first at the Goldschmidt geochemistry conference in Paris.

A crucial turning point against Carthage in 210 B.C. gave the Romans control over many of the lucrative Spanish silver mines. Accordingly, after 209 B.C., the lead isotopes from Roman coins show they had come from the Spanish locations – which bear hallmark signatures in the precious silver.

“Before the war we find that the Roman coins are made of silver from the same sources as the coinage issued by Greek cities in Italy and Sicily,” said Westner. “But the defeat of Carthage led to huge reparation payments to Rome, as well as Rome gaining (great) amounts of booty and ownership of the rich Spanish silver mines.

“From 209 B.C. we see that a majority of Roman coins show geochemical signature typical for Iberian silver,” she added.

The drawn-out victory of Rome over Carthage and Hannibal during the Punic Wars set the Republic on a course for huge economic and military hegemony, added the scientists.

“The massive influx of Iberian silver significantly changed Rome’s economy, allowing it to become the superpower of its day,” added Westner. “Our work gives contemporary scientific proof of the rise of Rome.”

Two of the scientists involved in the work, Thomas Birch and Gleur Kemmers, wrote a piece in Alchemist, a publication of the London Bullion Markets Association, in 2014. They explain that although the silver in the coins from two millennia and longer ago is above 99 percent, the traces of alloy elements like copper and lead indictes provenance.

"The variation in the composition and isotopic signature of the coins can be related to that of geological sources, namely ore deposits," they wrote. "This is an entirely new approach."