You already know of the Black Death that swept through Europe in the 14th century. This terrible plague resulted in over 50 million deaths and is still remembered to this day as one of the most catastrophic illnesses in history. Well, recently archeologists made an astonishing discovery that shows skeletons from around 3800 BC that contained Yersinia pestis (a bacteria that causes the plague). This discovery suggests that pestis lineages were established during the Bronze Age which means the plague had an earlier outbreak which had a major effect on migration across Europe and Asia. During that period, there was a sudden spread of steppe herders from Eastern Europe to Western Europe between 3000 and 2500 BC, to this day scientists were uncertain what may have caused this sudden migration, Johannes Krause, a German geneticist says that pandemic might be a reasonable explanation.