The Black Death, or bubonic plague, was a deadly plague that swept through Europe between 1347 and 1351. The plague originally came from central and eastern Asia. Traders unknowingly brought the disease to Mediterranean ports. From there it quickly swept throughout much of Europe. Infected individuals usually died in a few days in terrible agony. Europeans did not yet have the knowledge of germs and viruses and struggled to explain the causes of this deadly plague. They also struggled with how to correctly treat those infected.

The Black Death ended the stability of European society. Some historians think the Black Death killed thirty percent (1/3rd) of Europe’s population—perhaps 25 million people. Other historians claim it killed up to sixty percent (2/3rds) of Europe's population. Thousands of towns and villages were left empty and abandoned. Many farming fields were left empty with no one to grow food. This caused sweeping changes all over Europe. The feudal system (feudalism), already weakened by the growth of cities, collapsed. Plague survivors found their skills in higher demand since there were fewer workers to fill necessary jobs and so they charged more for their labor. Instead of working for the rich, peasants now had other job opportunities.

Sadly, many Europeans blamed the Jewish people for the Black Death. They claimed, with no evidence, that Jews were spreading the plague by poising drinking wells. The pope ordered that Jews should not be killed or forces to convert, but he was ignored. In German towns, Jews were exiled or killed. In Strasbourg, 2,000 Jews were ordered to convert to Christianity or be burned to death.