Ancient DNA Cracks the Case of the Plague of Justinian

For the first time, researchers have found direct genomic evidence of *Yersinia pestis*, the bacterium behind the Plague of Justinian—history's first recorded pandemic—in a mass grave at the ancient city of Jerash, Jordan. This discovery definitively links the pathogen to the devastating outbreak (AD 541–750), solving a long-standing historical mystery. Analysis of ancient DNA from eight teeth revealed nearly identical strains of *Y. pestis*, confirming its presence within the Byzantine Empire and suggesting a rapid, widespread outbreak. The research highlights the enduring threat of plague, which continues to circulate globally, underscoring the cyclical nature of pandemics and the importance of understanding their origins.