Victims of the plague during the 1574 Siege of Leiden by the Spaniards black death black plague bubonic plague
Like no other disease, plague evokes terror. One of the most lethal illnesses in human history, it killed probably a third of Europe’s population in the 14th century. It may also have been one of the first agents of biological warfare: It’s said that in the 1340s, invading Mongols catapulted their plague dead over the city wall into Kaffa in the Crimea.
Yet the plague is not just a disease of the distant past. While cases tapered off in the mid-20th century, the World Health Organization (WHO) now classifies plague as “re-emerging.” No one is predicting another pandemic like the Black Death that devastated Europe. The WHO now records at most only a few thousand cases worldwide per year; and, if detected early, the disease can be treated effectively with antibiotics. But since the early 1990s, plague has returned to places – including India, Zambia, Mozambique, Algeria and parts of China – that had not seen it in many years or even decades.