Here’s what you’ll learn when you read this story:

• A metal detectorist unearthed a ninth-century C.E. gold coin pendant a few miles from the University of Cambridge.
• Curiously, although the pendant was made when the Vikings controlled the English kingdom of East Anglia, it depicts John the Baptist.
• It’s unclear why ninth-century pagan Vikings would mint a coin with a Christian figure on it.

Just what does the biblical figure John the Baptist have to do with medieval pagan Vikings? That’s the question raised by a metal detectorist’s discovery, in a hotbed of ancient Viking activity, of a gold coin pendant depicting the Christian martyr.

Discovered just a few miles from the University of Cambridge near Dunton, the ninth-century pendant is undoubtedly a Viking-era find. Thanks to its Latin inscription, there’s also no mistaking that the coin features an image of John the Baptist. Yet in historical terms, Viking rule and veneration of John the Baptist don’t logically go together, numismatist Simon Coupland told the BBC.

Coupland called everything about the coin pendant “fascinating, unique, and intriguing.” Coupland, who is well-versed in Carolingian-era coins throughout Europe, especially those tied to the emperor Charlemagne—dated the John the Baptist find to the late ninth century thanks to its lettering, which matches that of other coins minted in the 860s or 870s.

The Latin inscription translates directly to “John, Baptist and Evangelist.” Coupland said that’s an odd choice for the day. “If you look at who is pictured on portrait coins of the ninth century in Western Europe it is the king, but not John, not Christ—that is a Byzantine Empire thing,” Coupland said. “And these imitations of gold solidus tend to be made by Scandinavians, who are not Christian at this point—so what are they doing depicting John the Baptist?”

The Vikings took control of the kingdom of East Anglia after the Great Heathen Army descended on England in the 870s, around the time when the coin was minted. “So now you see why it is such a mysterious find,” Coupland said. “It’s like a child with a hexagonal shaped object trying to fit it into squares when it doesn’t fit at all.”

Even choosing John the Baptist as a figure to depict on the coin is puzzling. “St. John the Baptist was Jesus’ cousin and his forerunner, who introduced him to a wider public by baptizing him in the River Jordan and after that, his wider ministry began,” Coupland said. “But a figure of John the Baptist on a coin is so unusual and remarkable—I don’t know of another John the Baptist from the Carolingian period. It’s bizarre—it’s not like anything else I know.”

The questions raised by this single gold coin could have lasting historical impact. Is something off in the accepted timing of history? Is something missing from the Viking connection to Christian tradition?

The metal detectorist turned it over to officials to run it through The Treasure Act 1996 process. The Norwich Castle Museum hopes, according to the BBC, that once the coin finishes the process of being declared a legal treasure, they can acquire it for the collection. Perhaps then, after further study, we can get some answers.