The Black Death, a global pandemic

The plague is a highly infectious pulmonary disease that was frequently fatal in the Middle Ages. It is estimated that the 14th century plague epidemic now known as the Black Death killed between one third and one half of the world’s population.

In the 1320s, major climate fluctuations led to the proliferation of a type of gerbil in the highlands of Tibet. These rodents carrying plague-infected fleas are believed to be responsible for the spread of the epidemic.

Due to the political and economic unification brought about by the Mongol conquests, the epidemic spread rapidly along trade routes.

In 1332, the plague ravaged northern India. It reached Kurdistan in 1338 and / Iraq in 1339. In 1342, southern India and northern China were hit.

In 1346, the Mongols laid siege to Caffa, a Genoese trading post on the Black Sea, and passed the plague on to the besieged inhabitants.

The Genoese brought it back to the West. The disease reached Constantinople in June 1347, /Messina in September, Genoa and Marseilles in November, Cairo at the end of the year, and Venice in January 1348.

The plague then spread in successive waves, moving inland from the major ports at the measured pace of medieval travel. The disease decimated Avignon in January 1348, / Paris in late August, and England in September.

The plague did not spread evenly; some regions far from the main trade routes escaped relatively lightly, such as Béarn.

The epidemic subsided somewhat over the winter of 1348-1349, only to resurface with a vengeance. In the summer of 1349, the plague reached Scotland, Ireland and Scandinavia. A year later, the settlements in Iceland and Greenland were hit in turn.

Meanwhile, the disease continued to spread through Southeast Asia, the Maghreb, Egypt, and the Arabian Peninsula.

There too, the human toll was horrific. It was long thought that the disease did not reach sub-Saharan Africa, but it is now known to have spread there from the ports on the east coast linked to Egypt and India.

The map of the plague shows how connected the medieval world was already. From Greenland to southern Africa and from Japan to Portugal, people were dying of the same disease – even if it took more than twenty years for it to spread over such a wide area.

In the end, only the American continent and Australia were spared, protected by their isolation from the rest of the world.