The Spread and Medical Reality of the Plague
The pandemic that struck Europe in October 1347, when twelve Genoese galleys put in at Messina with their crews already dying, was the first to reach a fully connected medieval world. Within four years it had reached Bergen and the Russian steppes, killing an estimated 25 to 50 million people along the way. Modern bacteriology has identified the pathogen — Yersinia pestis, a gram-negative bacillus carried by rodent reservoirs and transmitted to humans by the bite of the rat flea Xenopsylla cheopis — and modern epidemiology has mapped the demographic and biological detail of the catastrophe. The three articles in this section work from the molecule outward: they trace what the disease did to the body, follow the routes it took across the trading map of fourteenth-century Europe, and then describe how medieval physicians, surgeons, and civic authorities tried, with the resources of Galen, Hippocrates, and the Arabic medical tradition, to understand and contain it.
The disease and its vectors
The bubonic form of plague produced the egg-sized swellings in the groin, armpits, and neck that gave the disease its late medieval name: buboes, from the Greek boubon, “groin.” Patients suffered high fever, the vomiting of blood, the blackening of the tongue and the skin, and a fetid breath that contemporaries described as the smell of the tomb. The pneumonic form, transmitted by droplet infection from person to person, attacked the lungs directly and could kill in as little as twenty-four hours. The septicemic form, in which the bacterium overwhelmed the blood, was the swiftest, often producing death before the buboes had time to develop. Modern work — most influentially the genetic studies of Mark Achtman, Daniel Haensch, and the Berlin-based team that published in Nature in 2010–2011, and the synthesizing work of Ole J. Benedictow in The Black Death 1346–1353 (2004) — has confirmed the long-standing bacteriological identification of the pathogen while revising some of the older estimates of mortality and speed of transmission. The clinical distinction between the three forms, the symptoms they produced, and their relative weight in the medieval pandemic are explained in Bubonic vs pneumonic plague: what was the difference?.
Following the trade routes
The geography of the Black Death was the geography of medieval commerce. From Messina the disease moved by galley and by cart to Pisa, Marseille, and Barcelona by Christmas 1347; to Paris, Bordeaux, and the English Channel ports by the summer of 1348; to London, Winchester, and Bristol by the autumn of 1348; to the Hebrides, Norway, and Poland by the spring of 1349; and to the Russian hinterland of Novgorod and Pskov by 1351. Some regions held out: the kingdom of Bohemia maintained a sanitary cordon under Charles IV until 1351; the duchy of Milan and the bishopric of Liège imposed quarantines of varying strictness. Jean-Noël Biraben’s Les hommes et la peste en France et dans les pays européens et méditerranéens (1975–76) remains the indispensable reference for the European chronology, while Benedictow’s The Black Death offers the most detailed map of the routes and the regional mortality. The full account of the path of the pandemic, month by month and port by port, is the subject of How did the Black Death spread across Europe?.
Doctors, miasmas, and the birth of quarantine
Faced with a disease their inherited categories could not classify, the physicians of 1348 fell back on the medical theory of the day: a corruption of the air produced by the great conjunction of Saturn, Jupiter, and Mars in March 1345, an exhalation of the earth’s pores, an imbalance of the four humors. The response in the surgery was bleeding, purging, and the application of theriac, the complicated alexipharmic compound that had been used against poison since Galen. The response in the street was the burning of aromatic woods, the firing of cannons, the smell of vinegar, the wearing of pomanders, and — for those who could afford the service — the attendance of a medicus at the bedside. At the same time, and for the first time in European history, the cities began to organize a public-health response: Pistoia’s sanità of 1348, Venice’s Provveditori alla Sanità of the same year, the quaranta giorni imposed by Ragusa (Dubrovnik) on incoming travelers in 1377, the Marseillais quarantine of 1383. Luke Demaitre, in Doctoring the Black Death (2021), and Jon Arrizabalaga, in his work on the plague-tract tradition, have reconstructed the way learned medicine read the catastrophe. The full account of the medical response, the role of the universities, the place of folk and empirical healers, and the institutional history of the sanità is the subject of Medieval medical responses to the Black Death.
Articles in this section
- Bubonic vs pneumonic plague: what was the difference?
- How did the Black Death spread across Europe?
- Medieval medical responses to the Black Death