A man discovered a treasure of about 20,000 silver coins mixed with pearls and silver rings while digging for worms at his summer home in Sweden. The treasure dates back to the early Middle Ages and weighs around 6 kilograms, according to Livescience.

Sophia Anderson, an archaeology expert at the Stockholm County Board, said in a statement: “This is likely one of the largest silver treasures found in Sweden from the early Middle Ages. We do not yet know the exact number of coins, but I believe it could reach twenty thousand.”

Preliminary analysis showed that most of the silver coins date back to the 12th century, some bearing the inscription “KANUTUS,” the Latin name for Knut, indicating they were minted during the reign of Swedish King Knut Eriksson, who ruled from 1173 to around 1195.

Some of these coins are rare, including several “bishop coins” minted by influential bishops. According to the statement, these coins depict a bishop holding a crosier, a staff widely used by clergy as a symbol of their ecclesiastical office.

Lin Annerback, director of the Medieval Museum in Stockholm, told the Swedish daily Dagens Nyheter: “It is unique; we have no other medieval treasures from Stockholm.”

Annerback pointed out that Stockholm did not exist at the end of the 12th century but was officially founded in 1252 by a statesman and grew to become Sweden’s largest city by the end of the 13th century.

Regarding the reason for burying the treasure, Annerback said the late 12th century was a “turbulent period” because the Swedes were trying to colonize areas in Finland.

He added: “The mixing of silver with pearls and other items suggests it was a hidden personal wealth.”

Research on the treasure is ongoing. The Stockholm County Board will report the findings to the National Heritage Board, which will decide whether the state will compensate the man who found the treasure.

According to the Cultural Environment Act, anyone who finds an ancient silver piece or artifact is obliged to offer it to the state for recovery in exchange for financial compensation.