One reads:

In the year . . . of the hare [1339]

This is the grave of Kutluk.

He died of the plague with his wife Magnu-Kelka.*

After Issyk Kul, the Black Death remains a shadowy presence for the next several years; there is no reliable information on its movements, except that it always seems to be glimpsed moving westward through the steppe high grass. The year after Kutluk and his wife, Magnu-Kelka, died, one account puts the disease in Belasagun, a rest stop to the west of Issyk Kul where riders of the Yam, the Mongol pony express, changed mounts and Marco Polo’s father, Niccolo, and uncle Maffeo stopped on their way into China. A year or so later, the plague is spotted in Talas, to the west of Belasagun, and then to the west of Talas in Samarkand, a major Central Asian market town and crossroads where medieval travelers could pick up the road south to India or continue onward toward the Crimea. But only in 1346 do the first reliable accounts become available. That year one Russian chronicle speaks of the plague arriving on the western shore of the Caspian Sea and attacking several nearby cities and towns, including Sarai, capital of the Mongol Principality of the Golden Horde and home to the busiest slave market on the steppe. A year later, while Sarai buried its dead, the pestilence lurched the final few hundred miles westward across the Don and Volga to the Crimea, came up behind the Tartar army in the hills above Caffa, and bit it in the back of the neck.

The Genoese, who imagined that God was born in Genoa, greeted the plague’s arrival with prayers of thanksgiving. The Almighty had dispatched a heavenly host of warrior angels to slay the infidel Mongols with golden arrows, they told one another. However, in de’ Mussis’s account of events, it is Khan Janibeg who commands the heavenly host at Caffa. “Stunned and stupefied” by the arrival of the plague, the notary says that the Tartars “ordered corpses to be placed in catapults and lobbed into the city in hopes that the intolerable stench would kill everyone inside. . . . Soon rotting corpses tainted the air . . . , poisoned the water supply, and the stench was so overwhelming that hardly one man in several thousand was in a position to flee the remains of the Tartar army.”

On the basis of de’ Mussis’s account, Janibeg has been proclaimed the father of biological warfare by several generations of historians, but the notary may have invented some of the more lurid details of his story to resolve an inconvenient theological dilemma. Self-evidently—to Christians, at least—the plague attacked the Tartars because they were pagans, but why did the disease then turn on the Italian defenders? Historian Ole Benedictow thinks de’ Mussis may have fabricated the catapults and flying Mongols to explain this more theologically sensitive part of the story—God did not abandon the gallant Genoese, they were smitten by a skyful of infected Tartar corpses, which, not coincidentally, was just the kind of devious trick good Christians would expect of a heathen people. Like most historians, Professor Benedictow believes the plague moved into the port the way the disease usually moves into human populations—through infected rats.* “What the besieged would not notice and could not prevent was that plague-infected rodents found their way through the crevices in the walls or between the gates and the gateways,” says the professor.

The siege of Caffa ended with both sides exhausted and decimated by war and disease. In April or May of 1347, as the hills above Caffa turned green under a soft spring sun, the dying Tartar army faded away, while inside the pestilential city, many of the Genoese defenders prepared to flee westward. There are no accounts of life in the besieged port that fateful spring, but we do have images of Berlin in 1945 and Saigon in 1975, enough information to suggest what Caffa’s final days may have looked like. As the death toll mounted, the streets would have filled with feral animals feeding on human remains, drunken soldiers looting and raping, old women dragging corpses through rubble, and burning buildings spewing jets of flame and smoke into the Crimean sky. There would have been swarms of rodents with staggering gaits and a strange bloody froth around their snouts, piles of bodies stacked like cordwood in public squares, and in every eye, a look of wild panic or dull resignation. The scenes in the harbor, the only means of escape in besieged Caffa, would have been especially horrific: surging crowds and sword-wielding guards, children wailing for lost or dead parents, shouting and cursing, everyone pushing toward teeming ships, and beyond the melee, on the departing galleys, prayerful passengers hugging one another under great white sheets of unfurling sail, ignorant that below deck, in dark, sultry holds, hundreds of plague-bearing rats were scratching themselves and sniffing at the cool sea air.

Caffa was almost certainly not the only eastern port the plague passed through en route to Europe, but for the generation who lived through the Black Death, it would forever be the place where the pestilence originated, and the Genoese, the people who brought the disease to Europe. The chronicler of Este spoke for his contemporaries when he wrote that Genoa’s “accursed galleys [spread the plague] to Constantinople, Messina, Sardinia, Genoa, Marseilles and many other places. . . .