The coin was recovered after being put up for sale along with nine other Roman coins at an auction in Madrid, Spain, with a starting price of seven thousands euros.
The collection of coins were part of a haul of 65 coins found in 1985 inside a clay pot unearthed during expansion works at the Nossa Senhora da Piedade Sanctuary in Sanfins do Douro, in Alijó.
Despite the theft having been widely covered in the regional press at the time, the coins were never found, which police now know is because they had been taken straight out of Portugal and sold at a market in Vitória, Spain.
The subsequent sale at auction in Madrid was spotted by an eagle-eyed Portuguese historian and Professor at Porto University, who alerted the police of its catalogue listing.
The lot was described as an “extremely rare Roman coin, a one-of-a-kind Denarius minted during the civil war of the Roman empire in the years 68-69 A.D., known as the year of the four emperors, and with a bidding price of seven thousand euros”.
In turn, the police triggered the necessary mechanisms to bring the ancient coin back to Portugal.
It has now been handed over to an archaeology museum in Braga.
In a further twist, the PJ revealed, “unequivocal proof that this Denarius was an integral part of the Alijó treasury was only possible thanks to a 1983 study carried out by the aforementioned university professor even before the theft occurred, by comparing photographs taken at the time of the entire set of coins, with photographs sent by the Spanish police authorities, which allowed the recovery of not only that Denarius, but also nine other coins.”
PJ police collected the coins at the Portuguese Embassy in Madrid before handing them over to the Regional Directorate of Culture of the North, thus finally returning national historical and archaeological heritage and an important legacy to its rightful place, after a three-decade absence.