The "Black Death" is the name given to the pandemic of bubonic plague which devastated Europe between 1346 and 1353, with the peak years being 1348-1350. The plague was caused by the Yersinia pestis bacterium carried by the Oriental rat flea living on black rats. The infected rats from China and Central Asia had made their way to the Crimea and the Mediterranean with the cargo of merchants along the Silk Road. This incidence of bubonic plague is estimated to have wiped out between 30 and 60 percent of Europe's population at the time, reducing total world population from 450 to 350-375 million in the 14th century. Because the Yersinia pestis bacterium killed so many and required uninfected hosts in order to survive, the years of mass pandemic in Europeans ended quickly. However, the plague remained a perennial problem for Europeans until the 19th century. The bacterium would survive in the fleas of European rats but would inevitably infect a number of previously uninfected people every year, but never again to the extent of the Black Death years.
The most prominent symptom of the bubonic plague is the development of buboes in the groin, neck or armpits. A bubo is a swelling of lymph nodes that appears like a blister the size of an egg which oozed pus or bled when opened. An accompanying symptom is the development of acral gangrene and necrosis, the premature death of cells, leaving the skin and digits of the infected black and rotted.
Apart from the 75-200 million Europeans estimated to have perished from the plague in the 14th century, the years of the Black Death had a profound effect on the culture of Europe. Because 14th century science could not fully grasp why the plague had spread a number of explanations from God's wrath to Jews poisoning wells was offered by contemporary Europeans. These rumors about Jews led to some of the most infamous persecutions of the Medieval world. Hundreds of Jewish communities across Europe were destroyed in retribution for the perception that they had been the perpetrators of the Black Death.
In addition, the very real possibility that Europeans might at any minute become infected and die led to a widespread cultural phenomenon of living for the moment, as explored in Giovanni Boccacio's work The Decameron. Another cultural consequence of the Black Death was the artistic motif of the Danse Macabre, or Dance of Death. Numerous works of European art at the time depict dancing skeletons to remind people the fragility and brevity of their lives as well as the emptiness of earthly possessions and distinctions.