Black Death: The Medieval black plague that ravaged Europe and killed a third of its population. It was due to the plague which is caused by a bacterium (Yersinia pestis) transmitted to humans from infected rats by the oriental rat flea.
In 14th-century Europe, the victims of the Black Death had bleeding below the skin (subcutaneous hemorrhage) which darkened ("blackened") their bodies. The Black Death was characterized by gangrene of the fingers, toes, and nose.
Although some scientists have speculated that the Black Death was caused by other agents (including anthrax, typhus, and Ebola virus), DNA tests on 600-year-old teeth from victims of the Black Death have confirmed that Yersinia pestis was indeed the cause of the Black Death.