Researchers analyzed isotopes and DNA in the teeth of remains found in a mass grave from the Plague of Justinian, which swept through the Byzantine Empire A tooth from the Jerash mass grave site Greg O'Corry Crowe In the year 541 C.E., a terrible sickness swept through the Byzantine Empire . Now known as the Plague of Justinian , after the Byzantine emperor Justinian I , the pandemic faded and resurged for two centuries, killing tens of millions of people. It was the first documented outbreak of plague . A new study published in the Journal of Archaeological Science reveals details about the plague victims. Lessons about how their society worked and who was most vulnerable when disaster struck are still relevant to our modern health crises, the researchers say. In the sixth century C.E., the Byzantine Empire—the eastern half of the Roman Empire—covered most Mediterranean lands, including North Africa, southern Europe and Asia Minor.…