The Black Death is usually remembered as a European catastrophe: a disease that “arrived” at a single Mediterranean port in 1347 and then swept almost uncontrollably across the continent. Recent work in genetics and global history, however, has made it harder to tell that story in narrowly European or local terms. Studies of ancient DNA and modern Yersinia pestis lineages suggest that the pandemic’s roots lay in a “Big Bang” diversification around the Tianshan mountains in Central Asia and that, long before 1347, new plague lineages were already radiating out along Mongol supply routes and overland commercial corridors (Green e311). Rather than a mysterious visitor from an undifferentiated “East,” the Black Death was carried into the Mediterranean by the same systems of exchange, grain shipments, merchant galleys, and coastal entrepôts that sustained late medieval Afro-Eurasian commerce.

In this essay, I treat the Black Death as a tracer of Mediterranean connectivity by following one segment of that larger story, the disease’s movement from the Black Sea into the central and western Mediterranean between 1347 and 1349. Using Gabriele de’ Mussis’s account of the flight from Caffa to Genoa and Venice, Michele da Piazza’s chronicle of the 1347 outbreak in Messina, and related reports from Venice, Provence, and the papal court at Avignon, I argue that contemporaries inadvertently mapped the Genoese and Venetian maritime corridors that linked the Black Sea to Sicily, northern Italy, southern France, and the Iberian coast. In their efforts to explain why plague leapt from port to port, why cities like Messina and Venice were struck so hard, and why authorities tried to close harbours or ban outsiders, these writers reveal how densely integrated they understood the Mediterranean shipping world to be. The epidemic’s trajectory, I suggest, followed existing commercial routes and sailing rhythms rather than a single “entry event.”

To situate this Mediterranean corridor within its wider Afro-Eurasian frame, I put Monica
Green’s reconstruction of the plague’s Central Asian origins in dialogue with Samuel Cohn’s account of its movement into the Black Sea and Hannah Barker’s recent study of grain embargoes and Yersinia pestis in the Black Sea. Once we move our gaze away from a single European “arrival point” and follow Green’s global frame, the first step in this trajectory lies not in Sicily but in Central Asia. Genetic reconstructions suggest that in the thirteenth or early fourteenth century a major diversification of Yersinia pestis occurred somewhere in the Central Asia–Tianshan region, creating plague lineages that would later fuel the Black Death (Green e311). Green argues that these lineages did not lie dormant, waiting to be “introduced” to Europe in 1347, but were already being redistributed by the logistical systems of the Mongol empire, especially grain shipments that moved fodder and food along with their rodent populations, across Inner Asia and into the western steppes (e311–e312). In other words, before the disease ever touched the Mediterranean, it was already travelling inside imperial and commercial infrastructures that bound Central Asia to the Black Sea. 
 

Samuel Cohn’s synthesis of narrative and documentary evidence picks up the story at this frontier. In his introduction to David Herlihy’s lectures, he describes the plague moving along the Silk Road into the Mongol khanate of the Golden Horde, with its capital at Sarai on the lower Volga and then to the Black Sea (Herlihy 23). For the epidemic to become a true pandemic, it had to “cross water” to reach a seaborne network that could project it rapidly into entirely new ecological and social environments (Herlihy 23). Barker’s study on Black Sea grain trade and embargoes adds a further dimension to this reconstruction. Working with Genoese, Venetian, Byzantine, and Mamluk records, she shows that this Black Sea world was also structured by shifting embargoes and grain convoys. Between 1343 and 1347, Italian merchants and travelers could still cross the Black Sea even when bulk commodities such as grain often could not, while Venetian access to ports such as Tana was sharply limited under Golden Horde embargoes (Barker 117–18). From the perspective of Italian notaries and friars writing in Piacenza or Messina, much of this Black Sea politics remained opaque; what they could see most clearly and thus narrate most fully were places like Caffa and Constantinople. Therefore, their narratives of Caffa and Messina are shaped as much by these limits of access and information as by what they actually knew on the ground. Against this background, the following pages read de’ Mussis, da Piazza, the Cortusii, and Heyligen not simply as witnesses to mass death but as writers whose attempts to make sense of plague exposure reveal how they imagined Mediterranean connectivity from within those constraints.

In these modern reconstructions, ports like Caffa mark the hinge where an Inner Asian epidemic meets the Italian maritime world. It is at this hinge that Gabriele de’ Mussis, a notary from Piacenza who died in 1356, begins his story as one of the earliest writers to offer a connected account of how the plague entered Europe (Horrox 15). De’ Mussis never claims to have been physically present at Caffa; instead, he frames his Historia de Morbo as a moralizing meditation on divine wrath, written in polished Latin for a lay and clerical audience in northern Italy (Horrox 15). Yet this rhetorical purpose does not prevent him from registering concrete details about trade routes and port routines. In his account of the Tartar siege of Caffa, he famously reports that as the city collapsed into sickness, “some ships set course for Genoa, some for Venice and for other Christian lands” (Horrox 18–19). The phrasing is striking: de’ Mussis shifts into the first person plural, aligning himself with Genoese and Venetian merchants and taking collective responsibility for carrying the scourge home (Horrox 19). His narrative, then, is not an eyewitness report but a penitential geography, turning the usual routes of Genoese and Venetian commerce into the channels of God’s punishment. De’ Mussis also sketches, in highly compressed form, the pattern that Cohn later systematizes: an initial phase in which plague “infests first the ports, then the hinterland” (Herlihy 24). The merchants’ ships are the first to be touched; once they dock, contagion radiates inland along social and economic lines of contact. Here, moral explanation and Mediterranean connectivity reinforce each other. The very intimacy that structured Mediterranean port society—kin visiting recently arrived sailors or friends embracing after long voyages—becomes the mechanism of transmission. De’ Mussis describes how plague-stricken sailors, once they reached Genoa, Venice, and other Christian ports and “mixed with the people there,” poisoned “every city, every settlement, every place,” and how, after “we Genoese and Venetians” had returned home from these voyages, the returning merchants infected their own households (Horrox 19). Yet, as Hannah Barker cautions, de’ Mussis wrote from northern Italy and had no direct access to the grain routes and embargo politics around Tana, the main grain hub of the Golden Horde (Barker 117–18, 119–20). His dramatic focus on the siege of Caffa therefore reflects an Italian vantage point that obscures this upstream Black Sea grain traffic. In this way, a single, stylized episode at Caffa opens onto a broader mental map: a sea of Christian ports linked by regular shipping, in which the plague is imagined as following the same lines as letters and goods.

If de’ Mussis provides a macro-level picture of the Black Sea–Italy connection, Michele da Piazza offers a much more localized view from one crucial node: Messina. Da Piazza, a Franciscan cleric writing in Sicily, composed a chronicle covering the years 1347–1361, and his account of the first outbreak at Messina is one of the richest port-side narratives (Horrox 35). Unlike de’ Mussis, da Piazza writes from within the city that he describes, and his intended audience seems to have been a regional lay and ecclesiastical public concerned with both political events and providential meanings. His chronicle opens the Sicilian episode with a precise scenario. In early October 1347, twelve Genoese galleys, “fleeing from the divine vengeance” unleashed upon them in the East, sailed into the harbour of Messina (Horrox 36). Da Piazza’s chronicle captures the moment when ships fleeing “divine vengeance” in the East reached a Sicilian harbour, but, unlike the diplomatic and notarial sources analysed by Hannah Barker, it is largely silent on the embargoes and grain convoys that had already begun to reshape Black Sea trade before those galleys ever appeared off Messina.

The sailors are already gravely ill; anyone who so much as speaks with them, da Piazza insists, contracts the deadly illness. Breath shared in conversation, the close proximity of those talking together, and the touch of contaminated goods all appear as routes of infection. Within days, Messinese citizens who boarded the ships or handled their cargo erupt in painful swellings and violent vomiting of blood; they die after only a few days, as do those who later wear their clothes or inherit their possessions (Horrox 36). Da Piazza interprets the disaster as God’s punishment, but his chronicle is just as much a description of how a maritime city works. His narrative takes for granted that Genoese galleys returning from the Black Sea will call at Messina; he does not need to explain why they are there, only that this time their arrival is fatal. That assumption aligns neatly with Ole Benedictow’s reconstruction of fourteenth-century shipping. Benedictow stresses that Italian galleys were high-speed vessels, averaging perhaps eighty or more kilometres a day and able to cover roughly 2,500 kilometres in a normal sailing month. On his estimates, the route from Constantinople to Messina is about 2,300 kilometres, a journey of some thirty-four days under typical conditions (Benedictow 154). As Benedictow notes, Genoese galleys “called especially at the port of Messina before putting to sea for their last stretch homewards,” making the Sicilian city a regular provisioning stop on the return route from the eastern Mediterranean (Benedictow 156). The dating in da Piazza’s chronicle thus dovetails with the logistical pattern suggested by Benedictow. A homeward convoy leaving the Black Sea or Constantinople in late summer could easily reach Sicily in early autumn 1347, well in line with the Mediterranean sailing season that he reconstructs for Italian galleys, bringing with it both infected crews and contaminated rat populations (Benedictow 154–56). Barker’s reconstruction of Golden Horde embargoes and Venetian grain convoys shows that Black Sea grain traffic reopened in spring 1347; if plague crossed the Black Sea during this renewed trade, as she suggests, the autumn convoy described in da Piazza’s chronicle looks like a downstream leg in the same chain carrying both grain and infection toward Sicily (Barker 120). 

Da Piazza’s narrative of what follows further illuminates how urban authorities and ordinary people thought about their own connections. Once the Messinese realize that the Genoese ships are killing them, they try to expel the intruders from the harbour. But the effort comes too late; the disease is already entrenched in the city (Horrox 36). Panic triggers a wave of flight into the countryside, even as the epidemic begins to move into other cities like Catania (Horrox 37). Here again we see the two-phase pattern that Cohn observes at a larger scale. In the first phase, plague rides with ships into ports like Messina; in the second, typically the following spring, it invades the hinterland from these maritime bases (Herlihy 24). Da Piazza records, sometimes with almost incredulous horror, how rural communities that had tried to shelter themselves from urban contagion nevertheless succumbed once traders and refugees arrived. Social and economic contact, not mere physical proximity, is the vehicle of spread.

Later Italian chronicles, also included in Horrox’s collection, extend this pattern up the peninsula and into the wider Mediterranean. The chronicle known as the Historia de novitatibus Paduae et Lombardiae, produced by the Paduan notaries Guglielmo and Abrigeto Cortusi in the mid-fourteenth century (the “Cortusii Patavini duo, sive Gulielmi et Abrigeti Cortusiorum” of Muratori’s edition), situates the plague within a providential framework similar to that of de’ Mussis and da Piazza: God first strikes distant unbelievers in the East, then sends the plague across the sea to chastise Christian regions and kingdoms, from the Veneto and Lombardy to the March, Tuscany, Germany, and France (Horrox 34). Yet the mechanism of this chastisement is explicitly commercial. They explain that the disease was “carried by some infected people who had travelled from the East,” whose mere sight, touch, or breath killed those they encountered, and they note that even contact with their houses and clothes could transmit the infection (Horrox 34). Guglielmo and Abrigeto Cortusi are likely writing for an urban audience concerned with civic fortunes, and they used Venice as the emblem of catastrophe, reporting, with deliberate exaggeration, that one hundred thousand people died there and that the city was left almost empty (Horrox 34). Crucially, they also mention attempts to halt movement between cities and to exclude outsiders from entering (Horrox 35). Such measures presuppose a highly mobile regional economy; only a world accustomed to incessant inter-urban travel would imagine that closing city gates or banning foreigners could affect the course of a disease.

Other testimonies shift the focus from Italy to the western Mediterranean. French and Iberian writers picture the plague as travelling along the southern French littoral and the Iberian west coast in what some describe as a single “fleet” of death-dealing ships (Horrox 9). Writing from the papal court at Avignon, Louis Heyligen reports that “no kinds of spices are eaten or handled, unless they have been in stock for a year,” because people fear they “might have come from the galleys of which I spoke” (Horrox 42, 45). The image of a unified, malign “fleet” is not, as Horrox stresses, a literal description of shipping movements, but a product of panic and hindsight that compresses many separate voyages into one haunting picture. Yet precisely as an image, it reveals how tightly observers linked the geography of risk to the geography of trade. Pepper and other eastern goods normally symbolized the wealth that flowed into western Christendom through Levantine and Mediterranean commerce. Under plague conditions they became suspected carriers of death. The same sea-borne connections that made Avignon a nodal point in papal and commercial networks also made it, in local imaginations, dangerously open to invisible eastern threats.

In conclusion, treating the Black Death as a tracer of Mediterranean connectivity changes both the scale and the texture of the story. Green, Cohn, and Barker shift the starting point away from a single “arrival” at Messina in 1347 to a longer, messier process in which diversifying strains of Yersinia pestis moved along Mongol supply lines into the Golden Horde and across an embargo-ridden Black Sea world. Their work shows that before any Italian chronicler ever heard of plague at Caffa or Messina, the disease was already travelling inside grain convoys, diplomatic negotiations, and shipping bans that tied Central Asia to ports like Tana and, eventually, to Genoese and Venetian harbours. The narrative sources themselves show how contemporaries experienced those networks on the ground: de’ Mussis, writing a penitential sermon from northern Italy, imagines the plague riding out of a besieged Caffa on Genoese and Venetian galleys, infesting “first the ports, then the hinterland,” and spreading through the intimate social routines of Mediterranean port life. Da Piazza, watching Messina’s harbour from within the city, fixes on the moment when twelve galleys “fleeing divine vengeance” brought a lethal cargo into a familiar provisioning stop, and his account of panic, flight, and rural contagion traces the same two-phase pattern from harbour to hinterland that Cohn reconstructs at a continental scale. The Cortusii in Padua and Heyligen at Avignon then push this logic outward, imagining Venice as a hollowed-out hub and the western Mediterranean as a coastline stalked by a “fleet” of death-dealing ships and suspect spices. Read together, these writers turn trade routes, convoy rhythms, and fears about foreigners and goods into narrative devices for making sense of exposure.

Seen in this light, the Black Death becomes a map drawn in fear. It remains a demographic and spiritual catastrophe, but it is also evidence for how fourteenth-century actors understood the Mediterranean as a web of ships, cities, and commodities that bound Christians and non-Christians into a single, vulnerable space. By setting genetic and logistical reconstructions alongside these port-side narratives, we can see both the power and the limits of Italian perspectives shaped by embargoes and restricted access to places like Tana. The pandemic that linked the Tianshan frontier to Caffa, Messina, Venice, Provence, and Avignon thus reveals not only the reach of late medieval commerce, but also the mental geographies through which contemporaries imagined their world and tried to locate themselves within it.