9. The Black Death Went Away for a While, but Kept Coming Back for Decades
By 1352, the Black Death had mostly burned itself out. Mostly, but not completely. Like a persistent ex turned crazy stalker, the Yersinia pestis bacterium continued to return to wreak more havoc in subsequent decades. There were further outbreaks in 1361 to 1363, 1369 to 1371, 1374 to 1375, 1390, and 1400. None of the recurrences were as horrific as the original mid-century one, but they were still pretty bad: each time they hit, they killed about 10% to 20% of the population. All in all, in the second half of the fourteenth century, the plague was introduced and reintroduced to Europe numerous times, arriving along the trade routes from China and Central Asia in multiple waves. Modern research suggests that climate fluctuations played a key role in those recurrences, as they affected populations of rats and other rodents infested with the plague-carrying fleas.
