The Black Plague
The Black Plague was one of the most devastating outbreaks ever to occur. It caused up to 75 to 200 million people to die. This disease, also known as "The Black Death", was most likely caused by rat fleas living on the black rats that were common on merchant ships. It was carried along the Silk Road and eventually became a big deal, causing more and more people to die off. The infected victims first show signs of black and purple spots that soon grew bigger and swollen, this outbreak caused someone to die in 2-7 days once infected. This continued for four more years until it died down in Europe by the early 1300's, but it never did completely vanish in England. By the time the disease had stopped spreading rapidly and calmed down, almost a whole third of Europe's population had died.