Plague of Justinian

The Plague of Justinian was a pandemic of bubonic plague that struck the Byzantine Empire and the wider Mediterranean world beginning in 541 CE, during the reign of Emperor Justinian I, for whom it is named. The disease reached Constantinople by 542, reportedly killing tens of thousands of the city's residents at its height and afflicting the emperor himself, before spreading through trade routes into Byzantine territories across the Mediterranean, the Near East and parts of Europe. Recurrent waves of the same pandemic continued to strike the region for roughly two more centuries, and modern genetic analysis of ancient remains has confirmed the responsible pathogen as Yersinia pestis, the same bacterium behind the later medieval Black Death. The pandemic's severe demographic and economic toll is widely thought to have weakened the Byzantine Empire's finances, army and administration during Justinian's efforts to reconquer former Roman territory in the west, and it survives in a detailed contemporary account by the historian Procopius.