The Black Death was a plague that swept Europe in 1347-1351. Historians are not sure what the plague was. They are also not sure what if it was a single disease.

The plague was carried by fleas on rats. It entered Mongol through Mongolian soldiers who were bit by fleas. It was spread into ports and the infected fleas boarded ships which caused a massive spread around Europe.

The plague spread through Europe very quickly and many of the people who cared for the sick like priests tended to die of it within a few days. It spread on trade routes like the Silk Road from Asia to Europe.

The Black Death killed almost everyone who was infected and killed 1/3 of the European population. It left large back splotches on their skin and caused them to vomit, have headaches, and fevers.

The people who survived the plague thought they were being punished for by God for their sins.