3.3 | The Justinian Plague
The plague led to 25 to 50% of people in the Mediterranean region perishing. Necrosis of the lips, fingers, toes, and nose were among the symptoms, along with the development of huge buboes. The Yersinia pestis bacterium, disseminated by black rat fleas, caused significant outbreaks of the bubonic plague. Many ancient tribes believed that spirit and God visited those who deserved their anger with sickness and disaster. Although there was little scientific knowledge of the outbreak at the time, factors including inadequate sanitation and hygiene contributed to its spread.