Herring bones from trading places in The Baltic Sea show that extensive trade started 400 years earlier than previously thought.

Historians have believed extensive herring trade started around 1200, later controlled by the Hanseatic League. New study shows that it was established already in the Viking Age.
“We found that this trade existed already around 800 AD, 400 years earlier, which really pushes back this extensive fishing,” says Doctoral Research Fellow Lane Atmore at the University of Oslo.
She is first author of the study, published today in PNAS, which shows that herring bones from western populations around Sweden and Denmark were found as far east in the Baltic as Truso in today´s Poland. Truso is known as an important Viking Age trade port.