Dids Rats or Catapulted Cadavers Bring Plague to Caffa?

[In 1346] 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 co-incidentally, 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....

* Khan Janibeg does have one stout modern defender, Mark Wheelis, a professor of microbiology at the University of California. The professor notes that in a recent series of 284 plague cases, 20 percent of the infections came from direct contact—that is, the victim touched an object contaminated with the plague bacillus, Y. pestis. "Such transmissions," he says, "would have been especially likely at Caffa, where cadavers would have been badly mangled by being hurled, and many of the defenders probably had cut or abraded hands from coping with the bombardment." Professor Wheelis also thinks the rat scenario favored by many historians ignores a crucial feature of medieval siege warfare. To stay out of arrow and artillery range, besiegers often camped a kilometer (six-tenths of a mile) away from an enemy stronghold—normally beyond the range of the sedentary rat, who rarely ventures more than thirty or forty meters from its nest. (Mark Wheelis, "Biological Warfare at the 1346 Siege of Caffa," Emerging Infectious Diseases 8, No. 9 [2002]:971–75.)

SOURCE: The Great Mortality: An Intimate History of the Black Death, the Most Devastating Plague of All Time, by John Kelly (Harper Perennial, 2006), pp. 8-9