WORLD HISTORY

Detailed explanation-1: -The plague is thought to have originated in Asia over 2, 000 years ago and was likely spread by trading ships, though recent research has indicated the pathogen responsible for the Black Death may have existed in Europe as early as 3000 B.C. READ MORE: See all pandemic coverage here.

Detailed explanation-2: -The plague that caused the Black Death originated in China in the early to mid-1300s and spread along trade routes westward to the Mediterranean and northern Africa. It reached southern England in 1348 and northern Britain and Scandinavia by 1350.

Detailed explanation-3: -The plague caused an epidemic in China in the 1330s, and again in the 1350s, causing tens of millions of deaths. The 1330s outbreak also spread west across Central Asia via traders using the Silk Road. Why might expanded trade have made disease more dangerous?

Detailed explanation-4: -The medieval Silk Road brought a wealth of goods, spices, and new ideas from China and Central Asia to Europe. In 1346, the trade also likely carried the deadly bubonic plague that killed as many as half of all Europeans within 7 years, in what is known as the Black Death.

Detailed explanation-5: -Modern research has suggested that, over that period of time, plague was introduced into Europe multiple times, coming along trade routes in waves from Central Asia as a result of climate fluctuations that affected populations of rodents infested with plague-carrying fleas.