There is a general pattern of plagues originating in the large population centers of Asia and then being carried to Europe by the "population pump" of the stepp

There is a general pattern of plagues originating in the large population centers of Asia and then being carried to Europe by the "population pump" of the steppes. E.g. when there is a period of good rains the livestock and people swell in size and then when drought comes they migrate westward. This creates waves of people, often bringing diseases. The mongols were just one example. There is evidence of the plague in Neolithic europe: https://www.sciencemag.org/news/2018/12/did-new-form-plague-destroy-europe-s-stone-age-societies https://www.sciencemag.org/news/2018/12/did-new-form-plague-... And some believe that there are references to the bubonic plague in the old testament, which recounts the story of a plague of "tumors" (e.g. boils) hitting the Phillistines and then they put gold rats in the ark and sent it away to be rid of the plague: https://biblehub.com/1_samuel/6-11.htm https://biblehub.com/1_samuel/6-11.htm