1,600-year-old coin discovered in Channel Islands features Roman emperor killed by invading Goths

Archaeologists in the Channel Islands off the coast of France have discovered two Roman coins — one featuring a caesar who was "bumped off" as a teenager and another depicting a Roman emperor who was killed by invading Goths.

The discovery of the coins and previous findings of Roman structures, including the remains of a fort, suggest that the Romans had set up shop on the small island of Alderney, the northernmost Channel Island in the Mediterranean.

"We're starting to think that the Romans were here to keep an eye on that little stretch of water between here and France," Jason Monaghan, an archaeologist with the excavation and secretary of Dig Alderney, a charity for archaeology on the island, told Live Science. "The ships coming up from the Mediterranean carrying cargo and oil and wine and things like that would have had to pass Alderney, so the Romans probably put a fort there in order to keep an eye on that trade route to stop pirates and things of that nature."

Archaeologists have been excavating at Alderney since 2008, but there's still more to uncover, Monaghan said. In 2017, electrical workers discovered Iron Age burials and parts of a Roman building, showing that humans have occupied the island for thousands of years, he said.

An excavation of the Roman-era building revealed that it had three rooms, a courtyard on one side, a paved area on the other and a garbage dump to the southeast. One of the coins was found in this dump: A silver coin, known as an "antoninianus" that dates to A.D. 255 and was worth two denarii, a standard silver coin minted during the Roman era. The coin features the bust of Valerian II — the grandson of Roman emperor Valerian, who named his son co-emperor and his teenage grandson caesar. However, Valerian II wasn't long for this world; he died two years later under suspicious circumstances.

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The coin of Valerian II is "a little bit bigger than my thumbnail," Monaghan said. "It's quite thin. It's got the head of the caesar, he was like an assistant emperor, and he was only a teenager at the time. He was bumped off a couple of years later."