7. The Black Death Kept Coming Back, In Tragic Wave After Tragic Wave
The Black Death had mostly burned itself out by 1352, and the worst was over. However, there would be tragic recurrences, and in subsequent decades, the Yersinia pestis would return time and time again, to wreak more havoc. New outbreaks flared up in 1361 to 1363, 1369 to 1371, 1374 to 1375, 1390, and 1400. None of the recurrences were as deadly 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.
A death toll of 10% to 20% every few years for half a century adds up. During 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.
Read too: Thousands Died From the Black Death in 1666, Leaving Behind Haunted Plague Pits in London.
