1. Mongol ruler Janibeg catapulted plague-infested corpses in the port city of Kaffa to infect his enemies.

2. The pandemic was called the Black Death because the illness turned its victims’ tongues black.

3. The Black Death was thought to be a combination of two plagues: bubonic and pneumonic. 

4. Cramped living conditions and poor sanitation encouraged the spread of the disease.

5. Monasteries were one of the few areas that escaped the disease due to their isolation.

6. Royalty kept safe from the Black Death by closing their residences to visitors and even staff.

7. The popularity of groups like the Flagellants, a religious sect who whipped themselves while praying for forgiveness, rose during the Black Death.

8. The Black Death killed an estimated 25 million people in Europe by 1351.

9. One quarter of the population of 100,000 in Paris, France, died from the Black Death.

10. The Black Death is widely believed to have been caused by infection with the bacterium Yersinia pestis.

11. The Black Death solidified the line between social classes in Europe as the rich were able to better protect themselves from the disease.

12. Anti-Semitism intensified through Europe as Jewish people were unjustly blamed for the rise of the Black Death.

13. The population of Western Europe did not return to its pre-plague numbers until the beginning of the 16th century.