The term derives from “quaranta giorni,” meaning 40 days, and traces back to the 14th century when the city of Dubrovnik, now in Croatia, was under Venetian rule. The Great Pestilence, or the Great Plague, as it was known at the time, was devastating Europe. As a form of protection, Dubrovnik declared that all ships and people had to be isolated for 40 days before entering the city. Later, the disease would be referred to as the Black Death — probably because of the gloom it brought, although some theorize that the “black” referred to the terrible dark bruising of the skin due to internal bleeding, a hallmark of the disease.

Between 1345 and 1360, the plague wiped out roughly half of Europe’s population. The cause was unknown, but it was clear that the disease was contagious. Once it took hold, it spread like wildfire. In Milan, doctors advised that victims should be walled up in their homes along with healthy family members — a measure that apparently worked, since Milan had the lowest death rate from the plague in all of Italy.

It would not be until 1894 that Alexandre Yersin of France’s Pasteur Institute would identify a bacterium as the causative agent while investigating an outbreak of the plague in Hong Kong. The bacterium, eventually named Yersinia pestis in his honour, is thought to have originated in Asia, where it found a hospitable environment in fleas, which would readily transmit it through their bites. Since fleas infested rats and mice, rodents that were regular passengers on ships, the disease spread throughout the Mediterranean and Europe.

Infection with the bacterium can take several forms, with “bubonic plague” being the most notorious. This term originates from the Greek for “groin,” due to the characteristic swellings of the lymph glands particularly in the groin, an area close to the legs, where flea bites are most likely to occur. In “septicemic” and “pneumonic plague,” bacteria enter the bloodstream and can be transmitted from person to person, especially though the coughing associated with pneumonic plague.

When science fails to find an explanation for a phenomenon, superstition and quackery rush in to fill the void. And there certainly was no scientific explanation for the plague in the 14th century. The Church decreed that the Black Death was punishment for human sin. Lepers, because of their outward signs that resembled the plague, were blamed, as were astrological alignments and volcanic eruptions.

“Flagellants” believed God’s punishment could be avoided by stripping to the waist and whipping themselves as they marched from town to town. Jews were also targeted, accused of poisoning wells. Many Jewish communities in Europe were exterminated in hopes of bringing an end to the plague. In Cologne, thousands of Jews were burned alive after being accused of starting the plague. Black cats also became victims. They were thought to be witches in an animal form, casting their spell on the population. Since cats were a natural enemy of the disease-carrying rats, hunting them actually increased the spread of the plague.

As far as treatments went, there were none. Since the plague was often accompanied by a terrible smell, people walked around with flowers under their noses hoping to ward off the stench and the disease. This, of course, did nothing. Neither did the burning of aromatic woods to purify the atmosphere. Other attempts to remedy the “bad air” included the ringing of bells and the firing of guns. Birds were released indoors so that the flapping of their wings would break up the pestilence. Bathing was thought to be dangerous, as was the consumption of olive oil. And one of the most bizarre pieces of advice given to men was that if they valued their lives, they must preserve their chastity. Apparently no such advice was given to women.