<p>The Black Death was one of the worst pandemics in human history. In the 14th century, at least 75 million people on three continents perished due to the painful, highly contagious disease. Originating from fleas on rodents in China, the “Great Pestilence” spread westward and spared few regions. In Europe’s cities, hundreds died daily and their bodies were usually thrown into mass graves. The plague devastated towns, rural communities, families, and religious institutions. Following centuries of a rise in population, the <a href="https://www.thoughtco.com/current-world-population-1435270" data-component="link" data-source="inlineLink" data-type="internalLink" data-ordinal="1">world’s population</a> experienced a catastrophic reduction and would not be replenished for more than one hundred years.</p><h3>Origins and Path of the Black Death</h3>The Black Death originated in China or Central Asia and was spread to Europe by fleas and rats that resided on ships and along the <a href="https://www.thoughtco.com/along-the-silk-road-167077" data-component="link" data-source="inlineLink" data-type="internalLink" data-ordinal="2">Silk Road</a>. The Black Death killed millions in China, India, Persia (Iran), the Middle East, the Caucasus, and North Africa. To harm the citizens during a siege in 1346, Mongol armies may have thrown infected corpses over the city wall of Caffa, on the Crimean peninsula of the Black Sea. Italian traders from Genoa were also infected and returned home in 1347, introducing the Black Death into Europe. From Italy, the disease spread to France, Spain, Portugal, England, Germany, Russia, and Scandinavia.<h3>Science of the Black Death</h3>The three plagues associated with the Black Death are now known to be caused by bacteria called Yersinia Pestis, which is carried and spread by fleas on rats. When the rat died after continual bites and replication of the bacteria, the flea survived and moved to other animals or humans. Although some scientists believe that the Black Death was caused by other diseases like anthrax or the Ebola virus, recent research which extracted DNA from the skeletons of victims suggests that Yersinia Pestis was the microscopic culprit of this global pandemic.<h3>Types and Symptoms of the Plague</h3>The first half of the 14th century was marred by war and famine. Global temperatures dropped slightly, decreasing agricultural production and causing food shortages, hunger, malnutrition, and weakened immune systems. The human body became very vulnerable to the Black Death, which was caused by three forms of the plague. Bubonic plague, caused by flea bites, was the most common form. The infected would suffer from fever, headaches, nausea, and vomiting. Swelling called buboes and dark rashes appeared on the groin, legs, armpits, and neck. The pneumonic plague, which affected the lungs, spread through the air by coughs and sneezes. The most severe form of the plague was the septicemic plague. The bacteria entered the bloodstream and killed every person affected within hours. All three forms of the plague spread quickly due to overpopulated, unsanitary cities. Proper treatment was unknown, so most people died within a week after infection with the Black Death.<h3>Death Toll Estimates of the Black Death</h3>Due to poor or non-existent record-keeping, it has been difficult for historians and scientists to determine the true number of people that died of the Black Death. In Europe alone, it is likely that from 1347-1352, the plague killed at least twenty million people, or one-third of Europe’s population. The populations of Paris, London, Florence, and other great European cities were shattered. It would take approximately 150 years-into the 1500s- for Europe’s population to equal pre-plague levels. Initial plague infections and recurrences of the plague caused the world’s population to drop by at least 75 million people in the 14th century.<h3>Unexpected Economic Benefit of the Black Death</h3>The Black Death finally lapsed in approximately 1350, and profound economic changes took place. Worldwide trade declined, and wars in Europe paused during the Black Death. People had abandoned farms and villages during the plague. Serfs were no longer tied to their previous plot of land. Due to a severe labor shortage, serf survivors were able to demand higher wages and better working conditions from their new landlords. This may have contributed to the rise of capitalism. Many serfs moved to cities and contributed to the rise in urbanization and industrialization.<h3>Cultural and Social Beliefs and Changes of the Black Death</h3>Medieval society did not know what caused the plague or how it spread. Most blamed the suffering as a punishment from God or astrological misfortune. Thousands of <a href="https://www.thoughtco.com/judaism-4133178" data-component="link" data-source="inlineLink" data-type="internalLink" data-ordinal="3">Jews</a> were murdered when Christians claimed that the Jews caused the plague by poisoning wells. Lepers and beggars were also accused and harmed. Art, music, and literature during this era were gruesome and gloomy. The Catholic Church suffered a credibility loss when it could not explain the disease. This contributed to the development of <a href="https://www.thoughtco.com/christianity-4133210" data-component="link" data-source="inlineLink" data-type="internalLink" data-ordinal="4">Protestantism</a>.<h3>Scourge Spread Across the World</h3>The Black Death of the 14th century was a tremendous interrupter of worldwide population growth. The bubonic plague still exists, although it can now be treated with antibiotics. Fleas and their unknowing human carriers traveled across a hemisphere and infected one person after another. Survivors of this swift menace seized the opportunities that arose from altered social and economic structures. Although humanity will never know the exact death toll, researchers will continue to study the epidemiology and history of the plague to ensure that this horror never happens again.