By Dorsey Armstrong, Ph.D., Purdue University
In 1346, a Bubonic Plague pandemic was occurring to the northwest of the Caspian Sea, the northeast of the Black Sea, and the Sea of Azov. In Europe, the Italian peninsula was the first to be hit by the plague. But, how did the plague reach the European world? Were it the sailors and merchants? Let’s find out.

A Guest from the Sea
In 1343, the Golden Horde army laid siege to the city of Caffa for two years. But then the Mongol forces were ravaged by a sudden plague. In an act of revenge, they decided to load up the plague-ridden corpses of their dead soldiers and catapult them into the city.
For the Caffa population, the use of plague-infected corpses as weapons was the last straw, and the survivors started leaving the city by the sea and returning to their hometowns.
A logical question to ask is how an infected ship’s crew could survive such a long journey from Caffa all the way to Genoa without everybody succumbing to the plague and being unable to continue?
Our best guess here is that the ships in question had a large and diverse group of people on board. The numbers must have been high enough that the infection couldn’t make its way through everyone all that quickly. The bubonic form seems to be the one form of plague from which someone might recover, with survival rates around 18–20 percent.
This is a transcript from the video series The Black Death: The World’s Most Devastating Plague. Watch it now, on Wondrium.
Nuova Cronica and the Black Death

As the plague made its first significant European incursion into Italy, it’s no surprise that Italian writers were the first to chronicle its progression. The Italian chronicler Giovanni Villani recounted the Black Death’s appearance in his history Nuova Cronica.
Villani was inspired to write a history of Florence on the occasion of the jubilee in Rome in 1300. On that occasion, Pope Boniface VIII issued many papal indulgences in honor of Christ’s nativity.
Villani states it occurred to him that Rome seemed to be in decline, while the fortunes of Florence were rising. And since there wasn’t any book dedicated to the history of this city-state, Villani decided to commit his knowledge to paper.
Learn more about the plague’s effects on the medieval church.
A Detailed History of Black Death
What’s amazing about Nuova Cronica is the level of detail and the amount of data Villani provides. In late 1347-early 1348, he turned his attention to the Black Death, which had appeared in Italy’s major port cities around September-October 1347, and was in full force by December. His chronicle ends with the following paragraph:
Having grown in vigor in Turkey and Greece; and having spread thence over the whole Levant, and Mesopotamia, and Syria, and Chaldea, and Cyprus, and Rhodes, and all the islands of the Greek archipelago; the said pestilence leaped to Sicily, Sardinia, and Corsica, and Elba, and from there soon reached all the shores of the mainland and many lands and cities were made desolate. And the Plague lasted till—
And there it stops. Villani left a blank space, clearly planning to fill in the end date of the Great Mortality. But he himself died of the plague in 1348, and so the chronicle remains incomplete. Villani’s brother Matteo went on to add accounts of events to the Cronica until he also died of the plague in 1363.
The Plague Hits the Italian Peninsula
At the end of 1347, people living on the Italian peninsula were starting to recognize that this pestilence was not going to burn itself out quickly, and it was not going to remain contained or limited to port cities.

The example of the island of Sicily makes this clear; the plague arrived there when Genoese sailors docked in the port city of Messina in October 1347. By the end of that year, the whole island was ravaged when Messina citizens fled into the Sicilian interior to escape the plague. All they did was cause it to spread more quickly.
The first wave of the plague struck Italy particularly hard, but what seemed like the end of days was only the beginning of horrors that would last for at least a generation. In this very first wave, the French port of Marseille was also struck.
Learn more about Jewish persecution during the Black Death.
Black Death: A Deadly March in Europe
It’s important to recognize this in order to understand how the Black Death continued its deadly march through the medieval world in 1347. Marseille was the gateway to France for the plague, and from there, to England, where the Great Mortality struck with astonishing virulence.
Since Marseille was an important sea and land trading hub, the arrival of the Black Death there in 1347 gave the disease an advantageous position from which to advance across Western Europe. Had Marseille avoided such early exposure to the plague, it’s possible that the Great Mortality’s advance might have slowed down, as news from Italy might have reached the westernmost points of medieval Europe a little sooner and allowed some countermeasures to take effect.
But because Marseille was affected at around the same time as the port cities of Italy, the Black Death gained a foothold and was raging across the landscape before people really understood what was happening.
Common Questions about the March of Black Death in Medieval Europe
Since Marseille was an important sea and land trading hub, the arrival of the Black Death there in 1347 gave the disease an advantageous position from which to advance across Western Europe.
Nuova Cronica was written by Italian chronicler Giovanni Villani. It’s a book about the history of Florence, but also discusses the appearance of the Black Death in Italy.
People living on the Italian Peninsula recognized that the plague was not going to burn itself out quickly, and it was not going to remain contained or limited to port cities. Many escaped to the interior parts of the peninsula, only to make the plague spread even more quickly.