Rene Schoen and his student Luca Malaschnitschenko were looking for treasure using metal detectors in January on northern Ruegen island when they chanced upon what they initially thought was a worthless piece of aluminium.

But upon closer inspection, they realised that it was a shimmering piece of silver, German media reported.

A dig covering 400 square metres (4,300 square feet) that finally started over the weekend by the regional archaeology service has since uncovered a trove believed linked to the Danish king who reigned from around 958 to 986.

Braided necklaces, pearls, brooches, a Thor’s hammer, rings and up to 600 chipped coins were found, including more than 100 that date back to Bluetooth’s era.

“This trove is the biggest single discovery of Bluetooth coins in the southern Baltic sea region and is therefore of great significance,” lead archaeologist Michael Schirren told national news agency DPA.

The oldest coin found in the trove is a Damascus dirham dating to 714 while the most recent is a penny dating to 983.

The find suggests that the treasure may have been buried in the late 980s — also the period when Bluetooth was known to have fled to Pomerania where he died in 987.

“We have here the rare case of a discovery that appears to corroborate historical sources,” said archaeologist Detlef Jantzen.

Bluetooth is credited with unifying Denmark. The Viking-born king also turned his back on old Norse religion and introduced Christianity to the Nordic country.

But he was forced to flee to Pomerania after a rebellion led by his son Sven Gabelbart.

Bluetooth’s lasting legacy is found today in smartphones and laptops — the wireless Bluetooth technology is named after him, and the symbol is composed of the two Runes spelling out his initials R. B. DM