Who resided in Ridanäs?: A study of mobility on a Viking Age trading port in Gotland, Sweden

Ridanäs was an important Viking Age trading port on the island of Gotland, Sweden, in use during the 7-11th centuries, CE. Excavations at Ridanäs have revealed the presence of two cemeteries containing over 80 individuals. This study uses strontium isotope data derived from tooth enamel to determine the prevalence of non-locals buried at this site. Tooth enamel samples from a total of 60 adults from Ridanäs were analyzed for strontium isotope ratios. In addition, archaeological faunal samples were analyzed to define the local bioavailable strontium isotope baseline range. Individuals were considered local if they fell within two standard deviations of the mean baseline data value. The mean of the local faunal samples was 0.712419 ± 0.0016. Results indicated that 8 of the 60 individuals were non-local to the site of Ridanäs and the island of Gotland. The eight non-locals were likely from areas in northern Sweden or Norway. Although migration was a hallmark of the Viking Age, data from this study indicates that non-local individuals were not buried at this trading port. The lack of non-locals may be due to the fact that foreign traders did not make permanent residency on Gotland, or that the Vikings on Gotland did not allow non-locals to take advantage of their trade economy.