These Bizarre Cures Were Supposed to Stop the Black Death

In October 1347, twelve Genoese trading ships dock at the Sicilian port of Messina. They're returning from the Crimea, where they were supposed to load spices and silk. When people come to the harbor to greet the new arrivals, they find almost nothing but corpses aboard — and the few survivors are barely conscious, covered in black, oozing swellings that form in the groin, armpits, and neck. Harbor authorities immediately drive the "death ships" back out to sea — too late. Whatever came ashore with those ships will go down in history as the Black Death, killing an estimated one-third of Europe's entire population within just a few years; some regions lose as much as half their population.

Nobody knows what causes the disease. Nobody knows how to stop it. Physicians, priests, and ordinary citizens turn to whatever seems plausible — from carefully reasoned, almost scientific-looking procedures to practices that are hard to believe from today's perspective. That exact desperation produces some of the strangest, most unsettling, and occasionally accidentally clever reactions in human history — and in the end, it reveals more about the Middle Ages than any date or battle ever could.

To understand why the cures against the Black Death look so bizarre, you have to understand how medieval people thought about disease in the first place. The existence of bacteria was completely unknown — the responsible bacterium, Yersinia pestis, wasn't identified until 1894 by the Swiss physician Alexandre Yersin, more than 500 years later. The dominant medical theory of the time was the so-called miasma theory: disease was thought to arise from "bad air" — foul odors, corrupted vapors, a kind of invisible poison in the atmosphere. Alongside this sat the ancient theory of the four humors (blood, phlegm, yellow bile, and black bile), traced back to Greek physicians like Hippocrates and Galen, still considered the medical gold standard more than a thousand years after their deaths. Anyone who fell ill was thought to have an "imbalance" of these bodily fluids — not an infection from a pathogen they could never have seen with the naked eye anyway.

Just how seriously these theories were taken is shown by a remarkable document: in 1348, King Philip VI of France commissioned the medical faculty of Paris — then one of the most respected medical institutions in Europe — to officially determine the cause of the plague. The scholars' answer, known as the "Paris Plague Report," was astrological: an unfavorable conjunction of Saturn, Jupiter, and Mars on March 20, 1345, had generated "corrupted air" that spread across the world. This wasn't some fringe opinion from random quacks — it was the official, highly official scientific explanation of the time, endorsed by the continent's best-trained physicians.

Together, these two theories — bad air and humoral imbalance — explain almost every "cure" attempted against the plague in the Middle Ages: if bad air is the cause, you fight it with good smells. If the humors are imbalanced, you draw the excess out.

One of the best-known supposed cures was "Four Thieves Vinegar" — a mixture of vinegar, garlic, herbs, and spices. Legend has it that four thieves who looted the homes of the dead during the plague rubbed themselves with exactly this mixture to avoid getting sick. Whether the story is true, nobody knows — but there happens to be a grain of real science buried in it: vinegar does have mild antimicrobial properties, and many of the herbs and garlic used have insect-repelling qualities, which could theoretically have kept fleas away too (the actual carriers of the plague) — a lucky coincidence, not deliberate medicine.

Far more gruesome was the so-called "Vicary Method": a live chicken was strapped directly onto a patient's plague buboes, in the belief that the animal would draw the "poison" out of the body. Some accounts mention pigeons used the same way, and sometimes the procedure was repeated multiple times a day with fresh animals if the patient's condition didn't improve. For the patient, it brought no relief at all — for the animal, it was a certain death sentence.

Another standard treatment was bloodletting — following the "imbalance of humors" theory, a vein was deliberately opened to drain "corrupted blood," often at very specific points on the body depending on where the bubo had formed. In already weakened plague patients, this often hastened death rather than preventing it.

Some physicians also relied on so-called bezoar stones — hardened deposits found in the stomachs of goats and other animals, believed to be a universal antidote against any kind of "poisoning" and sometimes traded at exorbitant prices. Others had toads or frogs placed on plague buboes, hoping the animal would "absorb" the poison — a variant of the chicken method with the same outcome: no effect for the patient, one dead animal.

And then there was the scent strategy: people carried small pouches of fragrant herbs, rose petals, and flowers — so-called pomanders — hoping the pleasant smell would ward off the "bad air." Some burned sulfur or aromatic wood in their homes day and night, believing the smoke would drive out the corrupted vapors. Wealthier households even kept goats indoors, believing the animals' strong smell would overpower and neutralize the plague miasma.

Few images today are as closely tied to the plague as the "plague doctor" with his distinctive beaked mask. What many people don't realize: this costume didn't even exist during the great plague wave of 1347. It was designed in 1619 by the French physician Charles de Lorme — more than 270 years after Messina. The long, beak-like attachment was stuffed with strongly scented herbs, flowers, and spices, following miasma logic exactly: people believed the filtered, pleasant-smelling air would protect against infection. The leather coat and gloves happened to offer some genuine physical protection from direct contact with flea bites or infected bodily fluids — another lucky coincidence, not a deliberate insight about transmission routes. The costume was mainly worn during later plague waves in 17th-century France and Italy, and, somewhat paradoxically, precisely because of that has become the pop-culture symbol of the entire plague era, despite never having witnessed the original 1347 catastrophe at all.

For many people in the Middle Ages, the plague wasn't a medical question at all, but a religious one: a punishment from God for humanity's sins. Out of this belief grew one of the most striking — and disturbing — reactions of the entire plague era: the Flagellant movement. Groups of believers marched through cities and villages publicly whipping themselves, sometimes until they bled, hoping this penance would appease God's wrath and halt the epidemic. What began as a spontaneous religious movement grew, in some cases, into organized processions with hundreds of participants moving from town to town, often led by self-appointed preachers of penance. The movement briefly became so powerful and uncontrollable that Pope Clement VI officially condemned it in 1349, because the Flagellants began to see themselves as a kind of substitute church, independent of priests and ecclesiastical authority.

Alongside this, the search for scapegoats flourished. Jewish communities in particular were falsely accused in many European cities of poisoning wells and thereby causing the plague — a conspiracy theory that led to brutal pogroms, including in Strasbourg in 1349, where hundreds of people were murdered, even though Jewish communities suffered from the plague just as severely as their neighbors. Pope Clement VI even issued two papal bulls explicitly rejecting these accusations as baseless — without managing to stop the violence.

These reactions show that, faced with an invisible, unexplainable threat, people didn't just turn to false medicine, but also to dangerous social explanations — a pattern that repeats throughout the history of pandemics, right up to the present day.

Amid all the useless and sometimes dangerous cures, there was exactly one measure that actually worked — even though nobody at the time fully understood why. In the Venetian-controlled port city of Ragusa (modern-day Dubrovnik), authorities introduced a radical rule in 1377: ships arriving from plague-affected areas had to remain anchored in isolation for 40 days before crew and cargo were allowed ashore. The Italian term for "forty days" — quaranta giorni — is the direct origin of the modern word "quarantine."

Authorities had no idea about bacteria or incubation periods — they acted purely on observation: ships kept isolated longer brought the disease ashore less often. Venice adopted the principle shortly after and built dedicated island stations for it, so-called lazzarettos, named after the island of Santa Maria di Nazareth, where the first such facility was established in 1423. Travelers and goods were completely isolated there, and letters and coins were sometimes even dipped in vinegar before being passed on — a surprisingly modern idea of disinfection, even if for entirely wrong theoretical reasons.

It's a remarkable historical irony: while physicians were busy with bloodletting, chickens, and incense, it was a pure administrative measure with no medical theory behind it at all that actually saved lives — and whose basic principle still gets deployed today, nearly 650 years later, with every new pandemic, from the Spanish Flu to COVID-19.

Whatever the plague revealed about medical ignorance, it changed social reality far more dramatically. The massive population loss — in some regions, one in two people died — led to an acute labor shortage Europe had never experienced before. Peasants and craftsmen who survived could suddenly demand higher wages, simply because their labor had become scarce. Landlords who had relied for centuries on an oversupply of cheap labor now found themselves forced to compete for workers for the first time. Historians see this shift as one of the triggers for the gradual end of the classic feudal system across large parts of Europe — a development that would have taken centuries otherwise, had the plague not abruptly accelerated it.

This new bargaining power didn't go unchallenged: when English landlords tried to artificially suppress wages back to pre-crisis levels through law (the Statute of Labourers of 1351), it directly contributed to the Peasants' Revolt of 1381, one of the largest popular uprisings in English history. The Church also lost some of its undivided authority — too many priests had died themselves or fled out of fear, while ordinary laypeople often had to improvise comfort and burial rituals during the crisis without any clergy available at all.

The Black Death, then, wasn't just a medical catastrophe whose "cures" proved useless — it was simultaneously a societal turning point that cracked open the rigid structures of the High Middle Ages and paved the way for changes that would shape Europe all the way into the Renaissance.

In the end, the story of plague cures isn't really a story about stupidity, but about desperation without tools. Every single one of these remedies — the vinegar, the chickens, the bloodletting, the flagellation, even the famous beaked mask — made complete logical sense within the knowledge available at the time. Only in hindsight, armed with knowledge of bacteria and transmission routes, do we see how far off the mark they were. And of all things, the only measure that actually worked came not from medicine, but from pure, unconscious observation by ordinary harbor officials who had never completed a single medical degree. A lesson that reaches far beyond the Middle Ages: sometimes it isn't the most convincing theory that saves lives, but the simplest precaution, consistently applied — even when nobody can quite explain why it works.