• A pandemic that spread to Europe and was most devastating from 1347 to mid 1351
• It killed off more than a third of Europe’s population
• Struck centralized cities the hardest while some isolated villages did not encounter it at all
• The Plague never really disappeared. New strains of disease had outbreaks every generation.
• Some later ones include the Italian Plague of 1629-1631, the Plague of London from 1664 to 1665, and the Plague of Vienna of 1679
• The Bubonic plague was caused by the bacteria Yersinia pestis that was inside fleas which traveled around mainly on black rats and humans.
• The symptom included the famous black lumps which were hemorrhages or clumps of blood flowing from ruptured blood vessels under the skin. The usual places include around the neck, armpits, and groin because those places situated the lymph nodes- places that are used to fight off infections.
• People who had and have immunity to bubonic plague also have a very high chance of having immunity to HIV because they have a mutation in their Delta 32 gene that prevents the bacteria from attacking the lymphocytes

Please read my article on Black Death (Bubonic Plague) History if you are interested.