The disease known as the plague has been stalking humanity for over 5,000 years, and there have been many outbreaks. In fact, there have been three pandemics caused by the bacillus bacterium Yersinia Pestis. The first was in the 6th century. It devastated the Byzantine Empire and was known as The Plague of Justinian. The third began in China in the mid-19th century and quickly spread throughout the world. But it is the plague that began in 1346 which killed more than 50 million people in just seven years that we refer to as the ‘Black Death’. The Middle Ages was a time of superstition, religious fanaticism and ignorance and so they thought it was the end of the world. In reality it was the largest pandemic in the history of humanity.