Eketorpsborg (Eketorps fort) is an iron age fort on the island of Öland, in the Baltic sea of the south east coast of Sweden. The fort was inhabited from around 300 CE to 700CE, and again in the middle ages. The fort has been reconstructed to show elements from across these periods of occupancy. Information about the fort and some great pictures and diagrams can be found in English: Introduction to Eketorps fort
In brief, around 400CE the fort was home to around 200 people and consisted of a circular stone wall, surrounding buildings for living quarters, stables, storerooms and workshops, as well as an open space with what may be the foundations for a religious figure. Outside the fort was a marsh which served as a defence and a water source. A portion was delimited by hazel sticks to serve as a holy spring. The bones of horses and other animals have been found in the marsh, probably the remains of sacrifices.
Sandbyborg (Sandby fort) is located on the south east coast of Öland. Its construction was probably rather similar to Eketorpsborg. The remarkable discovery was made that the entire population of occupants appears to have been massacred around 480AD, though few adult female bodies have been discovered. There is no sign of organised defence or plundering (ither than perhaps weapons, since few were found), or even burials of the bodies. The site appears to have been abandoned after the massacre, with no sings of the reuse seen at Eketorps fort.
In their report on the finds, archaeologists Alfsdotter, Papmehl-Dufay and Victor discuss how there were connections between the leading families in southern Scandinavia and the Roman empire, in particular through controlling metal imports. These were sourced, at least in part, through mercenary service in the Roman military. Evidence of contacts with the Roman Empire comes from finds bronze statuettes, glass beakers and gold coins. The decline of the Roman empire appears to have had a dramatic economic and political impact on this society and suggest that this massacre may have been a result of this instability.
Eketorpsborg: Swedish/English: Eketorps fort Facebook page
Sandyborg: English: Sandby fort massacre
Original report on Sandby fort massacre
Swedish Television also broadcast a documentary on Sandbyborg; in Swedish
Massacre on the edge of the Roman Empire