A Medieval Guide to Avoiding the Next Pandemic

By Kathryn Walton

After the devastating plague pandemic of 1348-51, popular guides for avoiding the plague circulated in various forms around medieval Europe. One example from medieval England told readers all they needed to know to avoid getting sick during the next pandemic.

The Black Death pandemic of 1348-1351 was one of the worst in recorded history. Scholars estimate that roughly half of the population of Europe died as it ran its course. It also fundamentally changed European society for years following. For more on how it altered the lives of medieval peasants, check out my feature here.


The disease – caused by the bacillus Yersinia pestis and transmitted by an infected flea – was frightening to say the least. The Italian writer Boccaccio tells us that those inflicted would break out in “certain swellings, either on the groin or under the armpits, whereof some waxed of the bigness of a common apple.” From here, the plague-boils would spread to every part of the body, turn black, and spell certain death for the individual who sported them.

The symptoms alone were gruesome enough, but Boccaccio stresses that this disease was even more frightening because of the rapidness with which it spread. It spreads, he writes, like “fire upon things dry or greasy.” Moving about not only when individuals “did converse and consort with the sick” but even with “the mere touching of the clothes or of whatsoever other thing had been touched or used of the sick.” You can read Boccaccio’s account in full in his Decameron, available here.

The disease was perhaps most frightening because the medical community was baffled by its appearance and could do little to stop its spread. They blamed it on everything from the movement of the planets, to bad smells, to sin. In 1348 the medical faculty of the University of Paris issued a compendium of opinion that suggested the pandemic was caused by “a major conjunction [lining up] of three higher planets in Aquarius.” In the same year, the physician Gentile Da Foligno suggested it was caused by “a certain poisonous matter, which is around the heart and lungs and is generated there.” That year the professor of medicine at the University of Lérida Jacme D’Agramont also speculated on “whether its corruption or putrefaction was sent for our deserts in chastisement for our sins, or whether it came through the infection of the earth.” The range of responses gives a sense of how ill-equipped the medical community was to respond at the beginning of the outbreak.


After the pandemic had run its course the medical community and general populace were keen to ensure they were better prepared for next time.

The Rise of Popular Plague Treatises 

The devastation caused by that pandemic and the lack of ability of the medical community to respond effectively resulted in an outpouring of pandemic writing. People wanted to know why and how the pandemic had happened and how they could prevent one from happening again.

People were also keen to avoid catching the plague. The disease itself did not disappear once the height of the pandemic was over. A lack of medical knowledge about its actual cause and no effective medical technology to treat it meant that the plague continued to ravage the world for centuries after the end of the Black Death. So, doctors and other less professionally trained individuals began to produce tracts informing people how to avoid and treat this disease.


In England, treatises in both Latin and English circulated. Formal and respectable medical treatises produced by university-educated physicians appeared in Latin. These treatises, however, were inaccessible to most members of the general population who could not read Latin and did not have access to prestigious doctors. And so, a sequence of popular medical treatises in English also circulated amongst the general populace and the various surgeons, apothecaries, cunning-men, wise women, and midwives who treated them. These were often translations of Latin texts that made extensive references to sometimes falsified authorities. If you want to read more about the range of medical manuscripts circulating in Middle English, check out Rossell Hope Robbins’ “Medical Manuscripts in Middle English.”

One of the most popular plague treatises, called De epidemia (or De pestilentia), was written by John of Burgundy sometime around 1365. It appeared originally in Latin but was quickly translated into English, French, Dutch, and Hebrew. To learn about the dissemination of this treatise read “Médecin sans Frontières? The European Dissemination of John of Burgundy’s Plague Treatise” by Lister M. Matheson.

A popular Middle English derivative of this text attributed to John of Bordeaux circulated widely in England in the years following the Black Death. This version was very much so intended for a popular reading audience. It was shorter, widely available, easy to read, and it offered advice that was understandable and easy to follow. Its survival in large manuscripts of popular literature also reinforces how widely it circulated. It would appear amongst romances, poems, saint’s lives, conduct manuals and other popular literature of the period. The version I use appears in British Library, Cotton Caligula A ii, which is a popular household manuscript from the mid-fifteenth century. It pairs this medical treatise with narratives of knights and griffons, instructions on good table manners, stories of saints and lions, and other entertaining or informative texts.


Advice from a Popular Plague Treatise

This treatise tells you everything you need to know to avoid getting sick during the next pandemic. It opens by telling readers how to avoid catching the plague:

If an outbreak of the plague has happened again, you can take the following steps to protect yourself. Don’t take baths and don’t sweat; both will open the pores of your body and let the venomous air get in. Avoid lechery too because that also opens the pores and lets the illness in. Don’t eat much fruit unless it is sour or new. Don’t eat garlic or onions or leaks or anything that is going to get you in a heat. Drink lots of fluids: cold water is best with vinegar of barley water. 

The treatise then informs readers how the sickness enters and impacts the body:

It explains that every person has three principal parts: the heart, the liver, and the brains. Each part has a place in the body where it expels waste: the heart under the arms, the liver between the thighs, and the brain under the throat. The sickness comes into the body through the air, makes its way to the blood and attacks the heart, then the liver, then the brains. Each part of the body will attempt to expel venoms through the cleansing part, but if it can’t, those places will break out in plague boils.

If this happens to you, and you catch this disease, the treatise gives the following advice:


If you feel a “prickling or flickering” of the blood that is the sign of the sickness. You should immediately bleed yourself to help expel the venoms. Do this right away because after 24 hours the sickness gets stuck in you and bleeding won’t help as much anymore. Once the boils show up you can still bleed, just be sure to bleed in the places where the venoms are expelled because you don’t want to accidentally let out the good blood and keep the evil blood in. So, if the boils are on your thighs that means the sickness is in your liver so let blood out of the vein in your leg. If they appear in your armpits it means its in your heart so you should bleed out of your arm or hand. 

After bleeding yourself in various places, have waters steeped with four herbs “Betony / Pympernell / Tormetyll /and Schabyose” because they are good for this illness. Be sure also to be careful what you eat. Don’t eat meat unless its just a little chicken cooked in water or freshwater fish roasted with vinegar. Drink tisane (barley water) or small ale, and if you must have wine, have white instead of red.

The treatise finishes by saying that if you do everything listed there and evoke the grace of God, you will be protected from the disease.

The Appeal of the Treatise 

The number of surviving examples of this treatise alongside the fact that it appears in household manuscripts of popular literature tells us that this text was extremely popular. This text was translated and copied and recopied amongst all kinds of different people who must have placed great weight in the advice that it offered. The advice probably didn’t really actually help all that much to ward off or treat the disease. Modern medical knowledge tells us that most of these prevention tactics and remedies would not have been all that useful in treating a bacterial infection. But the very existence of the treatise and the fact that it gave people something to do to ward off disease was evidently very appealing.

I think after having lived through the Covid-19 pandemic we are now better equipped to understand why it was so very popular. People were eager to do anything they could to ensure that a pandemic on the scale of The Black Death of 1348-51 never happened again. A document that promised to help a person avoid catching the plague and that provided advice for those who did catch it would have had vast appeal. The threat of a new pandemic hung over the heads of the medieval world for long after the Black Death was finished. This treatise must have been an important source of comfort.

Kathryn Walton holds a PhD in Middle English Literature from York University. Her research focuses on magic, medieval poetics, and popular literature. She currently teaches at Lakehead University in Orillia. You can find her on Twitter @kmmwalton.

Click here to read more from Kathryn Walton

Top Image: British Library MS Additional 47682  fol. 33v


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