A metal detectorist in Norway dismissed a rare 900-year-old silver coin as a button, before researchers realized it was a one-of-a-kind piece linked to Magnus Barefoot (also known as Magnus Berrføtt), the warrior ruler often called Norway's last Viking king.

The coin, found in a field near Utstein Monastery in southwest Norway, dates to Barefoot's reign from 1093 to 1103. It is the first coin of its type ever discovered on Norwegian soil, according to a December 2025 translated statement from the University of Stavanger Museum of Archaeology.

"It is a fascinating thought that we may be just one large treasure find away from having a completely different view of Magnus Berrføtt's coinage as well, and it underlines the importance of all new discoveries that are made," museum representatives said in the statement.

The button that wasn't

The metal detectorist, Morten Eek, found the object in April 2025. It came from the plow layer in the soil, about 4 to 6 inches (10 to 15 centimeters) below the surface.

One side looked bright and silvery, but the other was covered by copper and had a dark spot in the middle, giving it a button-like appearance. Eek took it home and placed it with other buttons, worn modern coins and pieces of scrap metal he had collected.

It was only months later, when Eek showed his treasures to his fellow metal detectorists, that they noticed the silver side looked like a medieval coin. Its design resembled an illustration in the 1865 reference work "Norge's Coins from the Middle Ages," by C.I. Schive.

The detectorists then contacted the University of Stavanger Museum of Archaeology, where researchers took a closer look.

A coin with a second life

To the experts, the coin seemed strange because someone had altered it after it was minted. A copper plate had been placed over one side, and the coin's outer edge had been folded around it. Two rounded notches on the edge show where a chain or loop may have been attached, suggesting the coin was later worn as jewelry.

Researchers could have removed the copper plate to see what was underneath, but doing so would have damaged the object's fragile state.

The artifact's unique transformation reveals "something about people's relationship to what was initially a coin," museum representatives said in the statement.

To investigate the coin's covered side, the team X-rayed it. The scan revealed a griffin, a mythical creature with the body of a lion and features of a bird of prey. The motif has sometimes been interpreted as the lion of St. Mark, a Christian symbol, but the museum noted that the animal on these coins closely resembles a griffin. In medieval Christian art, griffins were used to symbolize Christ's dual nature as both human and divine.

The visible side revealed a "cross-over-cross" motif, with double-lined arms and small semicircles or bowl shapes at the ends. The pairing of the cross and griffin is what makes the coin so rare.

"Two-sided coins with the motif combination of griffin and cross over cross are only known from four copies," the statement said, with one coin from the Sandur hoard, found in the Faroe Islands in 1863, and three others from Denmark's Mørstad hoard, which was found this past spring and contains nearly 5,000 coins.

The rarity of such coins "may tell us something about the extent of Magnus Berrføtt's minting," museum representatives said in the statement.

In total, about 100 coins, spread across 12 discoveries, are known from Magnus Barefoot's reign, according to the museum. That makes every new example valuable for understanding how coins were produced and circulated in Norway in the late Viking Age and early Middle Ages.

Magnus Barefoot is sometimes called Magnus Barelegs, thanks to the kilts he wore. He became king in 1093 after the death of his father, Olav Kyrre (also called Olaf III of Norway), whose reign was remembered as a relatively peaceful period. Barefoot followed a different path. Like his grandfather Harald Hardrada, the Norwegian king killed at the Battle of Stamford Bridge in 1066, Barefoot built his reputation through warfare.

Barefoot spent much of his reign campaigning overseas. He sought to extend Norwegian power across the western sea routes, including the Isle of Man and parts of the Irish Sea. The museum noted that he was associated with the saying that a king was meant "for honor and glory, and not a long life." His death reflected this, as he died at around age 30, in 1103, when he was ambushed and killed during a campaign in Ireland.

The coin points to more than Barefoot's military ambitions. According to the museum, it also reflected one of his domestic reforms. Earlier Norwegian rulers had reduced the silver content of their coins, but Barefoot restored a high silver standard, with coins that were around 90% silver.

Whether the coin was lost at the Utstein Monastery during Barefoot's lifetime is impossible to know. Because it was turned into jewelry at some point, it may have circulated for years, or even generations, after it stopped being used as money.

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