Research is underway to learn more about the origins of medieval sword found earlier this month at the bottom of a Polish river, which some experts believe may have belonged to the Vikings. 

The sword sports a “mysterious inscription” and is one of eight weapons of its kind discovered so far in Poland, the Provincial Office for the Protection of Monuments in Toruń, a city near the spot where the sword was found and itself a protected world heritage site, wrote in a translated announcement on Facebook. Workers unearthed the sword from the bottom of Poland’s Vistula River while dredging the port at Włocławek, which is about 30 miles from Toruń. 

Preliminary analyses of the weapon, having weathered centuries of corrosion, traced it back more than 1,000 years to the 10th century A.D., the culture office said. That period is significant for Poland, which did not exist prior to the formation that century of the House of Piast, the earliest known dynasty that settled in that area and began the first recorded reign over modern-day Polish land. Officials wondered in their announcement whether the sword may have borne witness to the formation of Polish statehood.

Weapons of this kind, with a simple blade that extends symmetrically from the base, are typically considered by historians to have roots in northwestern Europe. Their ties to Scandinavian and Franconian — a section of what is now Germany that formed during the Middle Ages — cultures helps historians paint a more detailed picture of how Poland came to be its own country. Scandinavian influences are thought to have left their mark on Poland during the medieval era, officials say, although the relationship between the Scandinavian Vikings and the region of contemporary Poland is somewhat obscure and continues to be a subject of interest for historians worldwide. 

The sword uncovered in Włocławek was examined more closely under an X-ray scanner, which revealed an inscription hidden beneath layers of corrosion. The inscription reads “U[V]LFBERTH,” which could be read as “Ulfberht,” a marking found on a group of about 170 medieval swords found mainly in northern Europe. Each dates back to the 9th, 10th or 11th centuries, and some experts have suggested that the word is a Frankish personal name, potentially signaling the weapons’ origins. However, much is still unknown about the weapons and where they came from, and not everyone is convinced that the sword once had links to the Vikings. 

Robert Grochowski, a Polish archaeologist, told the Warsaw-based newspaper Gazeta Wyborcza that even though these types of swords are often referred to as “Viking swords,” they were technically created in territories in today’s Germany and traded widely throughout Europe. They may have reached Central Europe, including Poland, this way, potentially by way of Scandinavia.

“I don’t know where the idea that the sword belonged to a Viking comes from,” said Grochowski, in translated comments. “Without detailed research, this is completely unjustified. It is difficult to say anything more than the fact that it is an early medieval sword.”

Researchers plan to continue studying the ancient sword at Nicolaus Copernicus University in Toruń. It will ultimately be preserved and put on display at a history museum in Włocławek.