Viking sagas, early Christian cults, and the movement of people in the 10th-13th-century Viking world

The Vikings are well known for their long-distance travels. Originating in Scandinavia, they took their shallow draft ships along the river networks and open seas to trade with Europe, Russia, Constantinople and the Mediterranean (Morcken, 1989). They also undertook raids and later invasion and settlement of coastal areas of the British Isles, Ireland and mainland Europe (Nordeide & Edwards, 2019; Price & Raffield, 2023). They headed west to discover lands previously unknown to Europeans, such as Greenland and the east coast of North America (Ingstad & Ingstad, 2000). However, they adopted Christianity in the 10th–11th centuries and gradually shifted from warlike raiders to more mainstream European societies. This is shown by their joining other European nations in collaborative events such as the crusades to the Holy Land, when the fleet of King Sigurd Jorsalfar of Norway reached the Kingdom of Jerusalem in AD 1110 (Murray, 2006). In this paper published by Geber's team, (Geber et al., 2023), we are drawn into the world of the early Christian cult of St. Olaf. King Haraldsson of Norway (c. 995–1030) was canonized as Saint Olaf after his death. On the island of Gotland in the Baltic Sea, six burials at the pilgrimage site of S:t Olofsholm dating from 10th to 13th centuries were examined. Two of the burials showed evidence for perimortem sharp force and projectile weapon trauma, and a further individual showed charring indicating the body had been exposed to fire prior to the burial. Olaf is recorded as visiting Gotland with his troops while converting the Gutes there to Christianity, with violence being recorded in the sagas collated in the Heimskringla. Oxygen and strontium isotope analysis of dental enamel was undertaken for four of the burials. The results for three individuals were compatible with spending their childhood on Gotland but would also be compatible with other regions of Scandinavia. In contrast, the strontium value in one older adult female was incompatible with the local range for Gotland but would be compatible with Iceland, south Norway, Denmark, south Sweden and parts of Britain. This exploration of a pilgrimage site associated with St. Olaf helps to link the legends and sagas associated with early Christianity in the Viking world. Ancient people would only undertake arduous journeys on pilgrimage if there was a good reason to make that trip. It seems quite possible that it was the nature of the people buried here that made S:t Olofsholm a site worthy of pilgrims traveling to it. We find evidence for migration and for weapon injuries in those buried at this pilgrimage site. In view of the historical texts about Olaf's conversion of Gotland, Geber's team argue that these individuals may have been involved in the Christian conversion of the island, so making the site worthy of pilgrimage. Data sharing is not applicable to this article as no new data were created or analyzed in this study.