The Plague that brought down mighty empires is thousands of years older than thought

The Plague is far older than previously known and later changed to become much more virulent—so virulent that it may have contributed to the decline of Classical Greece and the Roman and Byzantine empires and later killed off 30 to 50 percent of Europe’s population, a new study says.

The bacteria that causes the Plague, Yersinia pestis, diverged from the less-pathogenic Y. pseudotuberculosis bacterium about 5,783 year ago. That divergence, and therefore the bacteria’s possibility of infecting humans, is much earlier than scholars previously estimated.

While the Plague would go on to kill tens of millions of people in Europe and Asia, researchers have found DNA of Y. pestis in the teeth of a Russian person who died 5,000 years ago. They say that although the plague doesn’t appear to have been as prevalent or as virulent in the Bronze Age, even then it may have triggered migrations of populations in Europe and Asia and caused population decreases.