Researchers connect ancient coins to historic events
A Roman Denarius, one of the coins analyzed by researchers at McMaster University.
Andy Johnson, CTV.ca News
Published Sunday, December 12, 2010 7:57AM EST
Researchers at McMaster University are mapping the metallic DNA of ancient Greek and Roman coins, establishing a direct link from the currency to events that changed the course of history such as wars and even the collapse of the Roman Empire.
They have developed a technique that makes it possible to determine the precise metal content of ancient coins by bouncing subatomic particles off their surface. Repeated thousands of times over the course of weeks, the process begins to reveal exactly what the coin is made of.
And once the "metallic fingerprint" is complete, researchers can begin to link the coins back to the Mediterranean locations where the source metal was mined, said Spencer Pope, an assistant professor in the department of classics, and one of the researchers leading the project.
"As we learn more about the artifact we come to understand the coin itself a little better. And the other shoe to drop on that is to understand the origin and where the silver came from. We can then begin to better understand economic trade routes and particular patterns of trade and exchange in antiquity," he told CTV.ca.
Essentially, researchers can begin to reconstruct the story of the ancient coins and connect them to historic events, adding an Indiana Jones-esque flare to a field with a reputation for nerdiness.
The long-term goal is to create a database available to researchers, archeologists and historians around the world.
Pope and his colleagues are studying coins on loan from the McMaster Museum of Art. Most are Greek and Roman coins, some dating back 2,500 to 3,000 years.
By analyzing numerous coins the researchers are able to piece together whether the silver or gold bullion used to make the currency was acquired in large batches, piecemeal, or whether the coins were simply restruck from other coins.
That information helps form a picture of the civilization they came from, and the type of government and civil organization that existed at the time, Pope said.
"By understanding the composition we can begin to make conclusions about trade, the administration of the Greek city, whether this was a one-time effort from a leader of the city to secure a vast supply or constant efforts over a long period of time. And these questions can begin to inform us about the origins," Pope said.
Perhaps more exciting is the fact that the metallic composition of the coins can be linked directly to known events such as wars and recession, even the collapse of the Roman Empire.
Pope and his colleagues have mapped the contents of about 20 coins to far -- each one takes about a month. Among the batch is a Roman coin dating back to the Punic Wars between Rome and Carthage, between 146 and 264 BCE.
The period was one of great financial strain for Rome as it struggled to fund the war, a fact that is reflected in the coins minted during the era.
"A coin dating from this period has been determined to have a lot of base metals included," Pope said. "It's a silver coin, and if you look at it from the exterior it has the silver colour and it shines like a silver coin. But it has a lot of elements added, tin, lead, and this is what we can reconstruct as ancient inflation."
Coins dating back to when Sicily was under Greek rule also tell a fascinating story. Because the area was poor in natural resources and had none of its own gold or silver, the mint relied entirely on restriking other coins to create currency.
When those restruck coins are analyzed, researchers can draw informed conclusions about where the original coins came from.
Through their research, Pope and his colleagues hope to create a database that can be accessible by coin researchers around the world.
In theory, an ancient coin found in a shipwreck in the Mediterranean, for instance, could then be analyzed and its metallic DNA could be connected to the source mine where the metal actually came from.
Nerdy or not, that's exciting for Pope.
"We could become a real centre for activity here in Canada, thousands of miles from Greece and Italy but nonetheless with the know-how to get this done."