The Black Death was a devastating pandemic that swept through Asia, Africa and Europe from about 1330 to 1350. The disease was likely the bubonic plague and several other variations. By the time it ran its course the world's population was greatly reduced.
The exact point of origin is unknown but possible locations include northwest China, southwest China and the steppes of Central Asia. A known outbreak occurred in the territories of the Great Yuan Empire in 1331 raging through Mongolia and China. In 1334 more than 90% percent of the population or 5 million people died in the Hebei Province that surrounded Beijing. Three rounds of the epidemic cut the population by 60% in the region 1330 to 1350. Overall China lost about one third of its population. It was one of the contributing factors in the Mongols losing control in China and later paving the way for the Ming Dynasty.
The bacteria of the plague was spread by the Mongols and by traders along the Silk Road and on ships traveling to Europe and Africa. The bacterium Yersinia pestis was the specific cause of the bubonic plague and it is found in fleas which in turn were found on rodents such as rats. When an infected flea bit a human it took about four to six days for symptoms to develop including swollen lymph nodes and a black cyst where they were bitten. Then dark lumps called buboes formed on the skin all over the body. The disease affected the nervous system and death occurred in fifty to sixty percent of the victims.
The plague reached the city of Kaffa on the Black Sea by 1346. Kaffa was controlled by a group of merchants from Genoa, Italy with permission from the Mongols. The disease was introduced to Europe in October 1347 when 12 of the Genoan trading ships arrived in Messina with most of the crews dead and the remaining very ill. The Genoan traders also spread the disease with their ships that same year to Constantinople, Turkey, Alexandria, Egypt and the island of Cyprus.
The Black Death continued to race through Europe as it continued through Italy and by 1348 reached France and Spain. In 1349 it reached the British Isles, Norway and Germany. It reached Russia by 1350.
The same horror was seen in Africa as it spread from Alexandria through north Africa. It struck villages all along the Nile River and reached Cairo in 1348 wiping out more than 200,000 people or over one third of the city's population. It had also reached Tunis in 1348 and spread to the Middle East as it hit Gaza, Palestine and Syria. The disease reached Yemen by 1351.
By the time the pandemic ran its course devastating losses were everywhere. Europe had about 25 to 50 million die or about one third of the population. China lost about 35 million or about a third of the population. About 40 percent of Egypt's population was lost. The range for the death toll estimates world wide has ranged from 75 million to 220 million.