TAR AND VIKINGS. This article by Robin McKie in the Guardian (November 4, 2018) begins: “Vikings conquered Europe thanks to an unexpected technological innovation. They learned how to make tar on an industrial scale and used it to waterproof their longships so that they could undertake large-scale, lengthy pillaging trips around Europe.” The article is based on a paper by Andreas Hennius of Upsala University, published in Antiquity. Tartar has been used for millennia to waterproof boats. It was made in pits filled with pine wood, covered with turf and set on fire.
Hennius’s argument is based on recent archaeological finds. Output from Scandinavian tar pits increased dramatically at about the same time that Vikings began raiding other parts of Europe. Domestic tar kilns had been found in Sweden in the early 2000s. These dated to between AD 100 and AD 400. Much larger pits have now been found and dated to between 680 and 900, when the rise of the Vikings began. (As a reference point, the sacking of Lindisfarne monastery by the Vikings took place in 793 AD.)