How the Black Death Worked

Because Europe was trading with the East, some medieval Europeans were aware of a mysterious disease sweeping through Asia in the 1330s. From Central Asia, the disease moved along an established trade route, passing through Turkestan and the Black Sea Region (Crimea and the Byzantine Empire).

In 1347, Kaffa, a town in modern-day Ukraine that was a Genoese trading post, came under attack by a Tartar army. When the Tartars were killed by the plague, the Genoese at first rejoiced: God had answered their prayers and punished their enemy. But that celebration ended when the Tartars began launching the corpses of plague victims over the walls of the city, hoping that the smell of rot would kill everyone in town. The smell didn't kill the Genoese, of course, but the disease did. The panicked Genoese threw the corpses back or submerged them in water. But it was no use; they were already exposed. As the dying Tartars retreated, the Genoese fled by ship to Sicily, taking the deadly disease with them to Europe.

Kaffa wasn't the only eastern trading port on the Black Death's path, but Genoa's ships took the blame for bringing the pestilence. Once it hit Europe, the Black Death moved fast, traveling at an average speed of 2.5 miles per day (4 kilometers per day) [source: Duncan, Scott]. From the Mediterranean ports, the disease took two paths; one through France that eventually made its way to England and Ireland, and one through Italy that went to Austria and Germany.

Written accounts state that the disease was frightfully contagious, and that death occurred only a few days after symptoms appeared. Other than this, people seemed to have no idea what was happening. Many felt that God's wrath was ravaging the earth and that the end of the world was near. Some theorized that Jews were contaminating the water supply. Both of these ideas spurred extreme responses that we'll explore in the next section.

When people began dying in France, King Philip VI turned to the Paris College of Physicians, the most highly-regarded medical authorities of the time, to learn the cause. The physicians produced a report that blamed the mass deaths on an event that occurred at 1 p.m. on March 20, 1345 -- the triple conjunction of the planets Saturn, Jupiter and Mars in Aquarius. The report explained that Jupiter, a wet and hot planet, soaked up evil vapors from Earth. And Mars, a dry planet, ignited the vapors and spread them through the air, which is how Europe got enveloped in a fog of death.

Interesting -- a fog of death. So, how do you cure a fog of death? And how do you protect yourself from catching it? In the next section, we'll learn how people dealt with the ugly spread of the Black Death.