Excerpts from Books and Wikipedia
"In October 1347, its citizens huddled in terror as the enemy catapulted plague-ridden corpses over the city walls. They had died of a virulent pandemic, known as the Black Death, which had broken out in China a year earlier and swept over Asia. . . . Within weeks it had swept through Italy, and by June 1348 had reached France, Spain, and England. By 1351, between one-quarter and two-thirds of the European population had perished. . . . During the next 300 years, the Black Death returned regularly, more than a hundred times, before finally dying out in the 1700s." [1001 Days]