The Black Death or Bubonic Plague is a disease that is caused by a germ called Yersinia pestis. It is spread to humans by fleas from infected rodents. The disease causes swelling of the lymph glands. The Greek word for groin is boubon, which is bubonic. The first symptoms are headaches, vomiting, and later most horribly: the skin turns black.

The most devastating outbreak of the Bubonic Plague was in 1346-51. It began in Kaffa, a town on the Crimean Coast. By the end of 1348, the plague covered all of Italy and most of France. By 1350 it had largely passed out of western Europe; it ended in Russia around 1351.

Over 25 million people died throughout Europe and for a time cultivation became impossible due to a shortage of hands. Nothing like that has happened before or since. In the space of two years, one out of every three people was dead.

These general numbers disguise the uneven nature of the epidemic. Some areas suffered little, others suffered far more. Here are some examples.

Between 45% and 75% of Florence died in a single year. 1/3 died in the first six months. Its entire economic system collapsed for a time.

In Venice, which kept excellent records, 60% died over the course of 18 months: 500-600 a day at the height.

Certain professions suffered higher mortality, especially those whose duties brought them into contact with the sick - doctors and clergy. In Montpellier, only seven of 140 Dominican friars survived. In Perpignan, only one of nine physicians survived, and two of 18 barber-surgeons.