If a flea bites a non-immune animal, the animal will die. The black rat, a nimble climber, could scoot up mooring ropes; as a result, it was carried from India to the eastern Mediterranean and eastern Africa.
From Egypt, the rat and plague went by ship to Constantinople and to the ports of Europe. The European seaports knew that a wide-spread, deadly plague was raging in the East. India was depopulated, as were Mesopotamia, Syria, Armenia, and other neighboring countries. The plague did not hit Europe with full force until 1346, when a new route for overland trade with China provided rapid transit for flea-infested furs from China. Traders returned from Asia, China, India, and the Middle East to Genoa and Venice in Italy.
China’s population dropped by half, to 65 million people.
The Mongolian empire ceased to exist because of loss of life. The Black Plague itself recurred in England in 1361, 1443, 1528, and 1563, and in Italy in 1575. Indeed, in 1528, when the plague raged through London, Queen Elizabeth moved to Winsor and was isolated from all Londoners.
The concept of contagion itself did not even exist at this time. Certain professions suffered higher mortality, especially those whose duties brought them into contact with the sick – doctors and clergy.
In Montpellier, only seven of 140 Dominican friars survived.
In the Middle Ages, nobody understood the disease’s cause.
They guessed at ways to cure it, finally quarantining arriving ships for forty days.
The Black Plague of the Middle Ages is thought to have originated in India about 1332, but this is not certain.
There were reports of bubonic Plague outbreaks in China prior to that date. In the 1330’s, unusually dry, windy weather caused Chinese nomads to migrate in search of food and water, along with their pack animals and relocating, hungry rodents. The Plague is caused by bacteria normally resident in field mice, ground squirrels and marmots (rodents similar to woodchucks). Flea bites carry the germ from rodent to rodent, and it is normally not fatal to its hosts. The plague began to spread through cities after they attracted large numbers of scavengers, especially the black rat.