Between the years 1347 and 1353, Europeans experienced a disaster of catastrophic and unprecedented proportions: the plague. The plague was later known as the Black Death, and you will frequently see it referred to this way. However, “Black Death” is a term coined by nineteenth-century historians. It was not one used by contemporaries, so I will not use it in this page. The plague of the mid-fourteenth century was a world-wide pandemic, although I will focus here on the European experience. It is estimated that a quarter to a third of all people in Europe died during this epidemic. The plague caused massive disruption of the social, economic, and cultural fabric of Europe (and other parts of the world). For the next three centuries, the plague returned to Europe every fifteen to twenty years. This means that almost everyone who lived to adulthood in late medieval and early modern Europe would have experienced at least one plague epidemic. Subsequent epidemics were generally more localized than the first pandemic of 1347-51, which affected nearly all of Europe. The last plague outbreak in England for example, was in 1665. This is the epidemic that inspired Daniel Defoe’s eloquent Journal of the Plague Year. (For more on this epidemic, see here.) The decline in population due to repeated epidemics of plague kept the population of Europe below the levels of twelfth and thirteenth centuries until the seventeenth and eighteenth centuries.

Spread of the plague 1347-53, by Andrei Nacu. Wikimedia Commons.

If you are interested in current scientific explanations of the plague epidemics of the Middle Ages and early modern period, see here. In brief, the plague was caused by the bacillus now known as Yersinia pestis and had at least four forms: bubonic plague, pneumonic, septicemic and enteric. The most common form was the bubonic plague, which is characterized by “buboes” (swollen lymph nodes in the armpit or groin). These buboes, which were generally dark purple or black, are described in contemporary sources.  In bubonic plague, the Yersinia pestis is carried by infected fleas.

Medieval and early modern people did not identify bacteria or fleas as the causes of the plague, but this does not mean they were completely without explanatory resources. Pre-modern people turned to BOTH religion and medicine to explain and cope with the disaster that was the plague.

Bartolomeo Vivarini, St Roch and the Angel (1480). Sant’Eufemia, Venice. Wikimedia Commons.

Most pre-modern people (and here I include both ordinary folk and the educated elite, religious authorities and medical practitioners) believed that the plague was sent by God to punish humankind for its sins. This belief engendered a variety of religious responses to the epidemic. Priests and other religious leaders called on people to repent and reform their lives. They arranged special masses, sermons on the topic of sin and repentance, public prayers and penitential processions, both to try to avert plague epidemics and to try to stop plague epidemics that had already started. Some towns promised to build votive churches dedicated to different saints in return for ending plague. Some saints were particularly invoked by people frightened of the plague. One of the most popular of these saints was Saint Roch (or Roche or Rocco). Saint Roch died in 1327 (that is, before the first plague epidemic), but it was believed that his image averted an outbreak of plague in Constance in 1414. There were numerous churches throughout Europe dedicated to this saint between the fifteenth and the seventeenth centuries. (For a list, see here.) In Venice, a charitable group called the Scuola di San Rocco (School of St. Roch) was founded in 1415. This group took as its mission the care of the sick, and especially those stricken by plague. In 1485, the Scuola di San Rocco acquired the body of St. Roch and brought it to Venice. (When I say “acquired” I mean that they stole it from a church in Montpellier, France, but this is another story.) The remains were placed in the Scuola di San Rocco’s church. A new church was begun in 1517 and completed in 1550. It was decorated with scenes from the life of St. Roch painted by the artist Tintoretto. Every year, on August 16, the ruler of Venice came to this church and publicly prayed to St. Roch to keep the plague away from Venice. This is just one example of the importance of saints and of religious responses to the plague.

Although most medieval and early modern people agreed that God had sent the plague to punish human beings for their sinful behavior, this in no way precluded naturalistic explanations of the plague, or attempts to prevent and cure the disease using naturalistic methods. Indeed, most people believed that God acted through “natural causes.” And God did not expect people to patiently accept their fate and lie down and die! He expected people to actively seek medical preventives and treatments, even while they prayed for relief.

Many naturalistic explanations centered on the quality of the air. It seemed to many observers that only a change in the air could account for how so many people got sick with the same disease at the same time, how the disease spread so quickly, and how persons remote from one another fell ill in the same way. Hot, sticky, putrid air must be the cause of the epidemic. But what caused the air to become “pestilential”? One major explanation was that a particularly unusual configuration of the planets had caused a change in the quality of the air on earth, and that this had created the plague. This rare celestial event was the conjunction of Saturn, Mars, and Jupiter on March 20, 1345. (You might want to review the page on Astrology.) This conjunction was typically held out as the origins of the disease, which then never left Europe (or not until the eighteenth century). However, other celestial events, like comets, were often connected to subsequent outbreaks of the plague.

An anonymous depiction of a comet of 1664. Many authors blamed the Great Plague of London in 1665 on this comet. Wikimedia Commons.

The air might become putrid through earthly causes as well. Nasty vapors, known as “miasmas” from stagnant pools, decaying corpses, dung, filth, or the exhalations of sufferers themselves could cause plague. Frequently, in order to try to avert plague epidemics, or to stop them once they had started, local authorities would order cesspools cleared and streets cleaned of rubbish. During plague epidemics, the dead were often buried in large pits and covered with lime rather than being given traditional burials. This was because rotting corpses were believed to spread plague (whether or not the person had actually died of plague). In addition to civic public health efforts like cleaning the streets and burying the dead in mass graves, individuals were urged to take steps to make the air around them less putrid. People attempted to improve their micro-environment by lighting fires, fumigating rooms, or applying pomanders or nosegays to their noses. Fragrant odors were believed to dry and sweeten the deadly air. Also, many people believed that plague epidemics could be started by malicious people. It was possible for such people to deliberately poison the air or water and thus initiate plague epidemics. Such actions were typically blamed on Jews, Muslims, and lepers. These beliefs and accusations led to mass killings of all these groups throughout Europe.

Some doctors, and many laymen, also referred to contagion as a factor in the spread of the disease. However, their concept of contagion was not as specific as that of modern bacteriologists. Nor was a theory of contagion necessarily opposed to one of miasmas; many medieval and early modern writers slipped easily from one to the other. Miasmas, after all could be caused by the breath of plague sufferers. Plague, it was almost universally accepted, could be spread by direct contact, contagion in the strict sense, but that was only one way. This belief led to quarantines to try to stop plague from spreading. Sick individuals might be confined to their houses (or in later epidemics to specially built plague houses). People from areas where plague was present might be denied entry to other areas. For example, when there was plague in Florence, Florentines would not be allowed into other Italian cities. Similarly, in 1665, when plague raged in London, Londoners seeking to flee their city were turned away from other cities and towns. Many people were reluctant to be near anyone who had the plague, making medical care difficult. This was not universal. As the example of the Scuola di San Rocco demonstrates, there were people – clerics, doctors, nurses and lay people – willing to care for the sick, and many people were reluctant to abandon sick family members. However, it was very common for wealthy people to flee their houses in plague-stricken cities for country houses.  Belief that plague could be spread by people who had the disease also led to recommendations and regulations about burning a plague victim’s clothing and other possessions. Even those who strongly advocated quarantines and the banning of potential plague-carriers believed that the air was the most effective bearer of contagion, and that their proposed measures also improved most effectively the quality of the atmosphere. The removal of bad smells went hand in hand with the removal of plague sufferers

L0064667 Titlepage: Directions for the Prevention & Cure of the Plague
English tract on prevention of plague, 1665. Wellcome Library.

One of the confusing things about plague was that not EVERYONE got it. If it was caused by bad air, or by contagion, or both, why didn’t EVERYONE in a particular locality contract the disease? The general explanation was that some people’s constitutions rendered them more vulnerable to the noxious effects of bad air or to the poison of contagion. This meant people could try to avoid plague by strengthening their constitutions. When plague threatened, people tried (according to their available means) to adjust their diet and regimen to make them more resistant to plague. Between the late Middle Ages and the seventeenth century their were literally hundreds of plague tracts in Latin and every European vernacular that gave people instructions in how to prevent plague through proper diet and lifestyle, and how to treat and cure plague if you got it. Despite the high fatality rates of plague, people DID try to treat it. And there is some evidence that people who were treated stood a better chance of surviving than people who were not.

Abū ‘Abd Allāh Muḥammad ibn Muḥammad ibn al-Ḥaṭṭāb al-Malikī al-Ru‘aynī (d. 1547/954), Umdat al-rāwīn fī bayān aḥkām al-ṭawā‘īn (The Authority of the Narrators Concerning the Explanation of the Principles of Plagues) (National Library of Medicine MS A 80). This plague tract was written on the occasion of the occurrence of plague at the end of the year 1536-7/943.

Secular and religious approaches to the plague continued to exist side by side from the fifteeth through the seventeenth centuries. The Churches (both Catholic and Protestant) accepted that God often worked through natural means, and both religious and civic authorities cooperated on such issues as charitable relief of plague victims.


  • Read one of the most famous contemporary accounts of the outbreak of plague in the mid-fourteenth century, the introductory pages of Boccacio’s Decameron. (For more on the Decameron, see here.)


H. Avery, “Plague churches, monuments and memorials” Proceedings of the Royal Society of Medicine 59.2 (1966): 110–116.


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