section_path: Eurasian trends/Plague and disease/Second plague pandemic until 1500
section_name: Second plague pandemic until 1500
paragraph_text: Second plague pandemic until 1500
  
  Six centuries later, a relative (but not a direct descendant) of Yersinia Pestis rose to afflict Eurasia: the Black Death. The first instance of the second plague pandemic was between 1347 and 1351. It killed variously between 25% and 50% of populations. Traditionally many historians believed the Black Death started in China and was then spread westward by invading Mongols who inadvertently carried infected fleas and rats with them. Although there is no concrete historical evidence for this theory, the plague is considered endemic on the steppe. Currently there is extensive historiography of the Black Death's effects in Europe and the Islamic world, but beyond Western Eurasia direct evidence for Black Death's presence is lacking. The Bulletin of the History of Medicine explored the potential linking of known 14th century epidemics in Asia with the plague. One example is the Deccan Plateau, where much of the Delhi Sultanate 's army suddenly died of a sickness in 1334. As this was 15 years before Europe's Black Death but little detail about the symptoms, it is unlikely that this was an instance of bubonic plague. Meanwhile, Yuan China suffered from major epidemics in the mid-14th century, including a recorded 90% death rate in Hebei Province. As with the Deccan event, surviving accounts do not describe symptoms; so historians are left to speculate. Perhaps these outbreaks were not the Black Death but instead some other disease already common to East Asia at the time, such as typhus, smallpox, or dysentery. Compared to Western reactions to the Black Death, Chinese records that do mention the epidemics are relatively muted, indicating that epidemics were a routine occurrence. Historians consider the hypothesis of a Chinese origin of a westward-moving plague unlikely given the fragmentation of the Mongol Empire and the 5,000-mile journey between China proper and Crimea through sparsely populated Central Asia.
  
  The aftershocks of the plague continued to affect populations well into the early modern period. In Western Europe, the devastating loss of people created lasting changes. Wage labor began to rise in Western Europe and there was more emphasis on labor-saving machines and mechanisms. Slavery, which had almost vanished from medieval Europe, returned and was one of the reasons for early Portuguese exploration after 1400. The adoption of Arabic numerals may have been partially caused by the plague. Importantly, many economies became specialist, producing only certain goods, seeking expansion elsewhere for exotic resources and slave labor. While typically Western European expansion as a result of the Black Death is most discussed, Islamic countries including the Ottoman Empire also partook in land-based expansionism and used their own slave trade.