The Black Death, an epidemic of bubonic plague that throttled 14th century Europe, inalterably changed the course of world history. The plague, which most scholars believe was transmitted through fleas from Asia, had a death rate that approached 95 percent for its pneumonic variety. Abnormal heat waves contributed to the plague’s rapid spread throughout the 1330s and 1340s, and some afflicted areas would need hundreds of years to recover from the effects of depopulation.

The Plague in Asia

The Black Death first appeared in Mongolia in 1338. Within the next decade, the disease spread to China and India via infected fleas on rats living in cargo holds of trade vessels. Despite the lack of written records, researchers believe that the 14th century plague killed more than 90 percent of the population in places throughout China, with a final death toll in the millions. Furthermore, the devastation of the Black Death contributed to the downfall of the Mongol Empire, and hastened the rise of China's Ming Dynasty.

The Middle East

The bacteria that caused the plague, Yersinia pestis, thrives in warmer environments. The disease devastated the Middle East, killing more than 60 percent of Egypt’s population. Some researchers even believe that the Black Death originated in Egypt and cite a 1,500 BC medical text that references buboes as a symptom of a particular illness. A famous anecdote about the Black Death recounts how the Turkish Tatars launched plague-infected corpses at their opponents, Genoan Italians, who eventually carried the plague to Europe.

Great Britain

The Black Death killed more than one-third of Britain’s population, and its arrival in the late 1340s had a profound effect on the development of British culture. As a result of depopulation and its effect on the workforce, Britain’s standing as an international economic power plummeted, and the aristocracy passed longstanding wage laws as an attempt to compensate for the sudden demand in labor. In crowded London, where an unusually wet summer fostered ideal conditions for the plague bacteria, nearly half of the city’s 70,000 inhabitants succumbed. Strangely enough, certain parts of England, namely the Scottish Isles, remained relatively unaffected.

Continental Europe

The Black Death decimated the western world more than any other area, with death tolls in southern Europe approaching more than 60 percent of the population. So-called plague ships, newly arrived from Asia, imported the disease into Sicily, whose function as a trade center allowed the disease to disseminate and claim more than 30 million European victims. One-third of Europe’s total population expired as a result of the plague, with casualties in France, Spain and Italy reaching particular extremes. The plague in Paris, for example, killed more than 80,000 people in just one year.