The Black Death is one of the most devastating pandemics in human history, resulting in the deaths of an estimated seventy-five million to two hundred million people and peaking in Europe in the years 1346–53.

Although there are several competing theories as to the etiology of the Black Death, analysis of DNA from victims in northern and southern Europe published in 2010 and 2011 indicates that the pathogen responsible was the Yersinia pestis bacterium, probably causing several forms of plague.

The Black Death is thought to have originated in the arid plains of Central Asia, where it then traveled along the Silk Road, reaching the Crimea by 1343.

From here, it is most likely carried by Oriental rat fleas living on the black rats that are regular passengers on merchant ships.

Spreading throughout the Mediterranean and Europe, the Black Death is estimated to have killed thirty to sixty percent of Europe's total population.

In total, the plague reduces the world population from an estimated four hundred and fifty million down to three hundred and fifty to three hundred and seventy-five million in the fourteenth century.The aftermath of the plague creates a series of religious, social, and economic upheavals that have profound effects on the course of European history.

The plague will recur occasionally in Europe until the nineteenth century.