Blood and pus seeped out of these strange swellings, which were followed by a host of other unpleasant symptoms–fever, chills, vomiting, diarrhea, terrible aches and pains–and then, in short order, death.

“In men and women alike,” the Italian poet Giovanni Boccaccio wrote, “at the beginning of the malady, certain swellings, either on the groin or under the armpits…waxed to the bigness of a common apple, others to the size of an egg, some more and some less, and these the vulgar named plague-boils.”

Even before the “death ships” pulled into port at Messina, many Europeans had heard rumors about a “Great Pestilence” that was carving a deadly path across the trade routes of the Near and Far East.