A team did just that by showing that Byzantine silver found its way into Anglo Saxon coins by A.D. 700, according to an article in Antiquities.
Historians had known for decades that, from around A.D. 660 to 750, Anglo-Saxon England saw a surge in silver coins, after the area had long relied on gold.
Money Mystery Rory Naismith, a history professor at the University of Cambridge, had had an earlier theory about the coins' provenance.
"I proposed Byzantine origins a decade ago but couldn't prove it," Naismath says.
Naismath knew that there had been an "explosion" in trade and urbanization over that time period.
Other researchers had focused on tracking silver from central and western France, so he followed his Byzantine hunch.
But from where the silver had entered the currency stream remained a mystery.