Splendid Exchange, A

by Bernstein, William L

  Around the beginning of the Common Era, infected fleas or rodents somehow made the journey from the disease’s probable ancient reservoir in the Himalayan foothills to India’s Malabar Coast, where infected black rats scampered over mooring ropes onto westbound trading ships. The winter monsoon blew these vessels across the Indian Ocean to Alexandria (or alternatively, to intermediate ports such as the island of Socotra or Aden) quickly enough for the rats to survive and reestablish the disease on disembarkation. In AD 541, during the reign of the Byzantine emperor Justinian, the first convincing descriptions emerge of Yersinia pestis infection—the Black Death (so called because of the widespread hemorrhagic rash) emerged. The historian Procopius recorded that the “plague of Justinian” first appeared (at least to Western observers) in Egypt, just as would be expected from the maritime supply lines of the Eastern Empire, which ran through the ancient Red Sea route (the easier “Sinbad’s Way” through the Gulf being blocked by Byzantium’s archrival, the Persian Empire).10

  Procopius observed the outbreak firsthand: “About the same time [the winter of 541–542] there was a Plague, which almost consumed mankind.”11 Procopius clearly described the buboes—painful, inflamed swellings of the lymph glands, “not only in the groin (called the Bubo), but in the armpits, under the ear, and in other parts,” that are the disease’s signature.12 The lack of person-to-person transmission perplexed him:

  No physician, nor other, caught the disease by touching the sick or dead bodies, many strangely continuing free [of the disease] though they buried [the dead], and many catching it, they knew not how, and dying instantly.13

  This first epidemic was transmitted from human to human by fleas, a path that proved less rapidly fatal than the person-to-person pneumonic route that affected Europe in the fourteenth century. Wave after wave of pestilence swept through the Eastern Empire at intervals of five to ten years following the initial outbreak and thus affected the young, who had not yet acquired immunity, disproportionately. About one-fourth of Constantinople’s population died in AD 541–542—Procopius recorded peak death rates in the city of about ten thousand per day—and by the year 700 its population had fallen by half. Before the epidemic, Justinian seemed poised to reunify the empire; it is not too much of a stretch to conclude that Yersinia pestis was primarily responsible for dashing those hopes. The epidemic helped plunge Europe into the Dark Ages and provided a geopolitical vacuum into which the early adherents of Islam, protected from the disease by the desert climate (which is unfriendly to the black rat) and by a lack of large cities, could expand. The plague also aided the Muslims farther east; Procopius recorded its devastation in Persia, suggesting that succeeding waves of the pestilence may have abetted the historic Muslim triumph over that empire at Ctesiphon (in modern-day Iraq) in AD 636.14

  The Black Death, Act I: AD 540–800

  By the time the plague finally burned itself out in the Eastern Empire, its trade with the Orient had reached low ebb. In AD 622, the same year as the last wave of plague at Constantinople, the Quraish expelled Muhammad and his followers from Mecca and precipitated their hegira to Medina. Within eight years, the Prophet’s armies would control all of Arabia and close Bab el Mandeb to Western shipping for more than a millennium; over the next several generations, they would deny Westerners the Silk Road as well. The armies of Islam deprived Europe of the relatively open access to Asia it had enjoyed since nearly the beginning of the Common Era. The silver lining of this stinging defeat was that this isolation would protect Europeans from Asia’s reservoirs of plague for the next seven centuries.

  The hot, dry, and largely uninhabited Arabian Peninsula offered some protection against the disease, but the next venue of Muslim conquest, the densely populated Fertile Crescent, proved an ideal breeding ground for it. By AD 639, the plague raged through Syria, devastated the civilian population, and killed as many as twenty-five thousand Muslim soldiers. Caliph Omar, the Prophet’s second successor, attempted to recall his great military commander Abu Ubaydah from Syria in an effort to save his life. Although the caliph concealed his purpose by telling his general that he was needed for urgent consultation, Abu Ubaydah saw through the ruse and, unwilling to thwart the will of Allah, remained in Syria. He soon succumbed to the disease, as did numerous succeeding Arab commanders.15

  The plague may even be responsible for the schism in Islam. After Abu Ubaydah’s death, another general, Muawiyah ibn Abi Sufyan, overthrew Caliph Ali (the fourth successor of the Prophet, and also his cousin and son-in-law), cleaving Muslims forever into Sunni and Shiite camps. Had Omar been successful in saving the capable Abu Ubaydah from the plague, it is possible that Islam would not have suffered this tragic split.

  However much the “plague of Justinian” afflicted the newly triumphant warriors of Islam, it caused far greater damage to their Byzantine and Persian enemies. According to the historian Josiah Russell, “Neither Charlemagne, nor Harun, nor the great Isaurian and Macedonian dynasties could break the pattern set up by the flea, the rat, and the bacillus.”16 To the sword of Ali and the wealth of Khadijah must be added the Black Death, which killed the young religion’s enemies—the Byzantines and Persians—with far greater regularity than it killed Arabs.

  Within a few generations of the plague of Justinian, the bacillus had also spread eastward from India to China’s seaports. Convincing Chinese descriptions of the disease appear by the early seventh century, and although confirmatory demographic data are few and far between, it seems likely that the plague devastated the Tang at least as much as it did Byzantium. One observer reported that in AD 762 half of the province of Shantung succumbed; between AD 2 and 742, the Chinese population appears to have decreased by about one-fourth.17

  Then, nothing. The last wave of the plague engulfed Constantinople in AD 622 and the periphery of the empire in 767. After those dates, no further convincing descriptions of the Black Death in Christendom are found until the deadly invasion of the fourteenth century.

  Why, then, did the plague not reach Europe until the middle of the first millennium, having been endemic among Asian ground rodents for thousands of years? Why did the next epidemic not occur for another eight hundred years? And why, finally, was the plague of Justinian confined largely to the Eastern Empire in Europe, whereas the later medieval epidemic engulfed all of the Continent?

  First and foremost, plague is a disease of trade. Infected humans live no more than several days, infected rats no more than several weeks, and infected fleas no more than several months. In order to transport the bacillus to the next caravanserai or port, the human, rodent, and insect hosts must pass quickly across the seas and steppes.

  While the plague of Justinian did strike scattered cities in northern Europe, it did not ravage the whole Continent for two reasons. First, in Europe the disease was conveyed primarily over Mediterranean routes, and the way west and north was blocked by the Goths, Vandals, and Huns. Second, by the sixth and seventh centuries, the essential intermediate host, the black rat, had not yet expanded much beyond the Mediterranean littoral, and certainly not yet to the continent’s Atlantic ports.18 The saving grace of the plague of Justinian was that the organism did not gain a foothold in Europe’s population of ground rodents. In the fourteenth century, the Continent would not be so lucky. The centuries-long exclusion of European traders from Asia—the “Muslim quarantine”—ended with the Mongol conquests of the thirteenth century; the reopening of overland trade by the heirs of Genghis Kahn would in time loose the plague’s fury on a Europe now much more vulnerable to the disease.

  During the sixth century, the scourge emerged from the seas; in the fourteenth, it came overland. Political unification under the khans reopened the Silk Road, and along with the precious goods of China came the rats and fleas that infected the besiegers at Kaffa. Our understanding of exactly how the Mongols and their allies became infected is incomplete. McNeill believes that the steppe warriors acquired the disease in its ancient home among the ground rodents of
the southern Chinese and Burmese Himalayan foothills when they invaded that region from the north in 1252.

  In 1331, the first reports appeared of the plague’s return to China. Almost immediately, the disease began barreling down the Silk Road, now running smoothly under Mongol rule. The infected fleas hitched rides westward, here in the manes of warhorses, there in the hair of camels, and elsewhere on black rats nestled in cargoes and in saddlebags. Just as the long-distance goods trade was indirect, with silks and spices changing hands along the way, so too did the bacillus pause many times before continuing the next leg of the journey.

  McNeill believed that the caravanserais provided the essential link in the transmission of the disease and furnished sustenance not only to the camel and the trader, but also to the bacillus. At each caravanserai along the way, the plague devastated the workers, owners, and guests, and sped the progress of the outbreak by scattering the survivors in all directions and establishing the disease in the local ground rodent population. In 1338, seven years after the Chinese outbreak of 1331, an epidemic may have torn through a trading post near Lake Issyk-Kul (in what is today Kyrgyzstan), about halfway along the Silk Road. By 1345 the disease enveloped Astrakhan on the northern Caspian coast, and shortly thereafter, Kaffa.19, 20

  In 1346, the bacillus reached Kipchak’s troops at Kaffa, and they seemed to suffer a particularly malignant form of divine wrath. According to the chronicler of the plague Gabriele de’ Mussi, “The Tartars died as soon as the signs of the disease appeared on their bodies: swellings in the armpit or groin caused by coagulating humors, followed by a putrid fever.”21

  The ferocity of the epidemic among Kaffa’s attackers quickly forced them to abandon their siege, but before they did, they unleashed history’s most devastating bioterrorism attack. Again, de’ Mussi:

  The dying Tartars, stunned and stupefied by the immensity of the disaster brought about by the disease, and realizing that they had no hope of escape, lost interest in the siege. But they ordered corpses to be placed in catapults and lobbed into the city in the hope that the intolerable stench would kill everyone inside. What seemed like mountains of dead were thrown into the city. . . . the stench was so overwhelming that hardly one in several thousand was in a position to flee the remains of the Tartar army.22

  The attack may have been an act of inspired desperation, or, as the world’s most expert catapult engineers, the “Tartars” (Mongols and their allies) may simply have found their machines the most efficient mechanism available for removing corpses. By the thousands, Kaffa’s defenders soon suffered the same fate, and within a few months, the Black Death tore through Europe and the Middle East.

  The Black Death, Act II: 1330–1350

  After its arrival in Kaffa, there can be little doubt that its further spread was trade-borne. Among the few who survived the disaster at Kaffa were sailors who made their way back to their Italian home ports. Once again, it would be the much smaller stowaways on these vessels—black rats—that scampered down the ships’ ropes and transported the plague bacillus to the wharves of Europe and touched off the medieval era’s great apocalypse.23 One Franciscan monk, Michele da Piazza, recorded the moment of the Black Death’s arrival in Italy:

  In October 1347, about the beginning of the month, twelve Genoese galleys, fleeing from the divine vengeance which Our Lord sent upon them for their sins, put into the port of Messina. The Genoese carried such a disease in their bodies that if anyone so much as spoke with one of them, he was infected with the deadly illness and could not avoid death . . . and with them died . . . also anyone who had acquired or touched or laid hands on their belongings.24

  The moment a plague ship docked, it was forced onward. As soon as a city became infected, the survivors fled, and the disease spread yet farther. Recorded da Piazza, “The Messinese were so loathed and feared that no man would speak with them, or be in their company, but hastily fled at the sight of them, holding his breath.”25

  Europe proved far more hospitable to the bacillus in 1347 than during the plague of Justinian. In the interim, the Mediterranean maritime trading network had grown swift, reliable, and voluminous; relays of infected rats could be shuttled from port to port more quickly, more regularly, and in far greater numbers than eight centuries earlier.

  A half century before the outbreak, in 1291, a Spanish flotilla, led by the Genoese commander Benedetto Zaccaria, overcame a Moorish force near Gibraltar and opened the strait to western shipping for the first time since the Muslim conquest of Spain.26 This allowed “plague ships” to sail directly out the newly opened passage into the Atlantic and deliver doom to northern Europe.

  Whereas in the sixth and seventh centuries the black rat did not thrive much beyond the eastern Mediterranean, in 1346 it greeted its infected brethren wherever they disembarked and then transmitted the disease to the European ground rodent reservoir. This new ubiquity of the black rat set off a chain of recurrent outbreaks that was to last for centuries following the first onslaught. In addition, newly established pack animal routes served to spread the disease overland, probably via merchants in the early stages of pneumonic infection, at a rate of one to five miles per day across the continent.27

  Between 1347 and 1350, the disease swept slowly and inexorably north from Italy; as can be seen on the map on page 141, its course followed both maritime and land routes, traveling, as did ordinary trade goods, more rapidly by sea than by land. Some small communities were entirely wiped out, while many larger cities escaped almost unscratched; according to the best estimates, approximately one of every three or four Europeans perished during those years. Although the initial onslaught burned itself out by 1350, repeated outbreaks occurred in the following decades, and then at more widely spaced intervals, as also happened after the plague of Justinian. Venice lost one-third of its inhabitants in the outbreak of 1575–1577, and again in 1630–1631.28

  Nothing before or since terrorized Europe as did the first wave of the disease. That it was borne on ships was obvious; lord and commoner alike imagined the seas and ports teeming with merchant fleets bearing cargoes of death, and even in inland cities such as Avignon, newly arrived consignments of spices went untouched for fear that they harbored the disease. Just as the plague’s flea-borne transmission (which would not be elucidated until modern times) perplexed Procopius, so would ignorance of this mechanism appall Europeans. De’ Mussi recorded in amazement the story of four Genoese soldiers who temporarily left their unit in order to plunder. They then

  made their way to Rivarolo on the coast, where the disease had killed all the inhabitants. . . . They broke into one of the houses and stole a fleece which they found on the bed. They then rejoined the army and on the following night the four of them bedded down under the fleece. When morning comes it finds them dead. As a result, everyone panicked, and thereafter nobody would use the goods and clothes of the dead.29

  Which was probably a good idea, since the purloined clothes were almost certainly crawling with infected fleas. After the initial landfall of the bacillus in Italy, messengers arrived in cities yet untouched and told petrified townspeople of a tide of death moving slowly their way. So high was the first wave’s death rate that many thought it heralded the end of the world. The simple knowledge that some did survive the outbreak of 1346–1350 eventually lessened the terror of subsequent plagues, many of which were otherwise at least as awful as the first.30

  During the medieval era, ignorance about the mechanism of the plague condemned tens of millions of Europeans, Africans, and Asians to death from a largely preventable infection. The lack of scientific knowledge also fanned the flames of anti-Semitism and consigned Jews to man-made fates arguably worse than the disease itself. Theories abounded as to the source of the pestilence. Punishment for corporeal or theological sins was a perennial explanation, as were the evil eye and the “miasma” (poisoned, if colorless, air). But by far the most pernicious theory held that Hebrews were poisoning wells. This delusion ignited panic among
Christians. As a result, thousands of Jews falsely confessed to this imaginary crime under torture and then were burned at the stake or broken on the wheel. Typical of the deadly hysteria is the account left by a prominent German priest, Heinrich Truchess:

  On 4 January [1349] the citizens of Constance shut up the Jews in two of their own houses, and then burned 330 of them. . . . Some processed to the flames dancing, others singing, and the rest weeping. They were burnt shut up in a house which had been specially built for the purpose. On 12 January in Buchen and on 17 January in Basel they were all burnt apart from their babies, who were baptized.

  Truchess goes on in the same vein for several paragraphs, recounting almost identical atrocities in cities great and small, finally concluding, “And thus, within one year . . . all the Jews between Cologne and Austria were burnt—and in Austria they await the same fate, for they are accursed of God.”31

  As with the Australian rabbit population in the years following the introduction of the myxoma virus in 1950, multiple rounds of the Black Death relentlessly drove down the populations of the nations of Europe to a nadir in the requisite five generations—about 125 to 150 years—before a modicum of immunity allowed the reproductive rate to gain the upper hand over this grimmest of reapers. In Britain, for which we have the most accurate demographic data of the period, the population decreased by well over half—from about 5.5 million on the eve of the plague in 1335 to 2.1 million in 1455. Figure 6-1 plots the fall and recovery of the English population; note that it did not return to its pre-plague level until four centuries after the initial outbreak.