Infection did not stop the rise of the city state, perhaps in part because it assailed the young republic and its enemies alike, and involved local infections rather than new pandemic imports. But as Rome grew and conquered distant lands, this would change.
By the time Julius Caesar dismantled what was left of the Roman Republic, the city’s empire was one of the biggest the world had seen. More than 50 million people lived under Caesar’s rule, stretching from the Atlantic coast of Gaul to the headwaters of the Nile. Frederick Cartwright, a medical historian, describes “the makings of disaster”:
A vast hinterland hiding unknown secrets, among them the micro-organisms of foreign disease; troops who attacked into that hinterland and were attacked by the inhabitants; free transit by ship or along roads specially built for speedy travel; at the center a concentrated population living a highly civilized life yet lacking the most rudimentary means of combating infection.8
Roman merchants benefited from the Empire’s central highway, the Mediterranean Sea, which allowed for dramatically faster travel than even Rome’s roads. And common merchandise included slaves (more than 1 million from Caesar’s Gallic Wars alone) that were the perfect vessels for moving infection.9
The merchants traveled even farther than did Rome’s troops. They set up a trading station near modern Pondicherry in India in CE 14. Within a century, thousands of Romans may have been traveling to India each year. Pliny the Elder, adviser to Emperor Vespasian in the first century CE, noted extensive Roman imports from across the Indian Ocean. In an attack on trade deficits with Asia that might sound familiar today, he complained that “India drains more than 50 million sesterces a year from our Empire.”10 It was a sum greater than Caesar had demanded in tribute from Gaul after his conquest.
Caesar himself gave Cleopatra an outfit of Chinese silk reportedly so gauzy as to be see-through, setting a fashion trend that swept Rome.11 In 160 CE, Roman ambassadors traveled through Egypt and Ethiopia, across the Indian Ocean and north to Vietnam by sea, and then overland to Luoyang in Han China. Chinese chroniclers suggest they brought elephant tusks, rhinoceros horns, and turtle shells as gifts. The visit cemented the relationship of the world’s two greatest empires, between them home to half of the people on earth.12
There is a detailed description of the Roman Empire, known as Da Qin, from China. The Peoples of the West, published in the third century CE, reported:
The kingdom of Da Qin… has more than four hundred smaller cities and towns. It extends several thousand li in all directions. The king has his capital close to the mouth of a river. The outer walls of the city are made of stone.… [They have] a tradition of amazing conjuring. They can produce fire from their mouths, bind and then free themselves, and juggle twelve balls with extraordinary skill.…
The people cultivate the five grains, and they raise horses, mules, donkeys, camels and silkworms. This country produces fine linen. They make gold and silver coins. One gold coin is equal to ten silver coins. They have fine brocaded cloth that is said to be made from the down of “water-sheep.”… They regularly make a profit by obtaining Chinese silk, unraveling it, and making fine silk damasks.13
For all the titillation that the silk trade allowed Caesar, it also carried infection risk. Just as Roman merchants arrived in China in 166 CE, what might have been smallpox reached back to Europe, perhaps brought on its final leg by troops campaigning in Mesopotamia. Hammering the area just as the climate was cooling (reducing yields and, consequently, nutrition levels), that disease killed more than one in four people in parts of the empire.14
Contemporary accounts report that the Antonine plague (named after Emperor Marcus Aurelius Antoninus) spread from Persia to the Rhine, killing enough people that whole cities were abandoned and wars ceased for lack of healthy armies.
This was the first year that German tribes—the Marcomanni and the Quadi—broke through the Roman defensive positions on the border of the empire, a sign of things to come as Rome was struck again and again by epidemics.15 Around 250 CE, another in a series of plagues killed as many as half of the population of some cities as well as an emperor.16 Historian Kyle Harper reports that the Cyprian plague, as it has become known, involved violent vomiting and diarrhea, putrefaction of extremities, and victims becoming deaf and blind—which suggests it might have been a hemorrhagic fever in the same family as Ebola. He also notes that the plague coincided with German tribes breaking across the Rhine to devastate Gaul and penetrate both Spain and Northern Italy; Goths striking at Greece, Macedonia, and parts of the empire in Asia; and the Parthians conquering Roman territory in Mesopotamia and Syria.17
Adding to the burden of a cycle of plagues, the most serious strain of malaria, falciparum, spread slowly up the Italian peninsula over the thousand-year life of the republic and empire. It reached Rome around 400 BCE and Venice by 750 CE. As it spread to previously unaffected regions, it would kill off considerable numbers of the most vulnerable. One of the largest ancient Roman infant cemeteries discovered dates to about 450 CE. It’s in Lugnano in Teverina, seventy miles from Rome, and contains forty-seven babies, all buried in the same summer, nearly half of which were premature. Falciparum malaria frequently causes miscarriages in previously unexposed pregnant women. The oldest child found on the site was a girl aged two or three years old. Her hands and feet were weighed down under stones and tiles, perhaps to prevent the demon disease from escaping to cause further destruction. DNA tests confirm she had malaria.18
But it was a pandemic that finished off the empire. Justinian, who ruled from 527 CE to 565 CE, was the last emperor to semi-successfully stitch back together many of the lands that had been ruled in Rome’s heyday, including Italy, much of Spain, and North Africa to the Atlantic. His contemporary biographer Procopius wrote glowing official accounts of these victories as well as a considerably less flattering secret history that described his boss as “an unnatural mixture of folly and wickedness… deceitful, devious, false, hypocritical, two-faced, cruel, skilled in dissembling his thought.”19 On the subject of violence, “sooner could one number, I fancy, the sands of the sea than the men this Emperor murdered,” declared the biographer. Incessant and barbaric war sparked by Justinian depopulated large areas, says Procopius: “The whole earth ran red with the blood of nearly all the Romans and the barbarians.”20
But alongside the human violence came death by infection. In his History of the Wars, Procopius describes the terror that affected the period, beginning in 542 CE: “a pestilence, by which the whole human race came near to being annihilated.” This was an outbreak of Yersinia pestis, the plague of the Black Death, paying its first significant visit to Mediterranean shores in recorded history. (It may have previously visited Europe to ravage substantial Neolithic settlements linked by the new technology of the wheel five thousand years before.)21
The disease we typically refer to as “the” plague usually spreads via infected rats and fleas. Fleas pass on the plague through a bite, and when their host dies they hop off to find sustenance elsewhere, taking the bacillus with them. The fever that heralds onset appeared to be nothing significant, suggested Procopius. But not many days later, a “swelling developed; and this took place not only… below the abdomen, but also inside the armpit, and in some cases also beside the ears, and at different points on the thighs.” The condition progresses through high fever, muscle cramps and seizures, sometimes with vomiting. Parts of the body develop gangrene as the host begins rotting from within. Unlucky victims—often the majority without modern medical treatment—go on to coma and death.
The deadly nature of the plague helps keep it local—unless humans move it. As William Bernstein observed in his history of global commerce, “plague is a disease of trade.” To transport the bacillus to the next stop on the caravan route or port, “the human, rodent and insect hosts must pass quickly across the seas and steppes.”22 Camels may have played a vital role in transporting the plague bacillus over distances—they can catch the dise
ase and even infect humans directly if they’re slaughtered and eaten.23 But the plague still needs a concentrated population of rats and fleas to help it spread rapidly in new locales—and cities along ancient trade routes provided suitable conditions for that.
The outbreak of plague that spread across the empire originated in Asia. It was first recorded reaching Roman territory in Pelusium, which sat on the east side of the Nile delta.24 That was a scant 160 miles down the coast from Alexandria, to which plague quickly spread. Alexandria was the second largest city in the Mediterranean and a port that sent grain from the rich fields of the Nile floodplains across the Roman Empire. In turn, that meant the city teamed with cosmopolitan rats, which boarded ships bound for Constantinople, Rome, and beyond, well supplied with food. Without sea trade, the bacillus might not have made it much past Pelusium. But Alexandria’s rodents helped carry the plague to the ends of the empire.25
Procopius was in Constantinople at the time the plague reached the imperial capital and reports that the towers of the city walls were piled up with dead for lack of burial places. Again, the chronicler suggests survivors became wanton, “surpassing themselves in villainy and in lawlessness of every sort.”26 Nearly half of the city’s half-million strong population may have perished.27 (It should be noted Procopius remained privately of the opinion that the emperor was worse than the plague: “Some never were taken by the disease, and others recovered after it had smitten them. But this man, not one of all the Romans could escape… as if he were a second pestilence sent from heaven.”)28
In 1543, within a year of striking Constantinople, plague had reached Arles in Southern Gaul. And the disease reappeared again and again over the next thirty years. Out of 26 million of Justinian’s subjects, as many as 4 million died in the first two years and 5 million more within the sixty years that followed. Cities shrank to towns, towns to villages, and many villages disappeared altogether. Land under cultivation across the empire as much as halved.29
The plague helped unravel Justinian’s re-knitting of empire. The army that could be supported by a diminished economy was one-third the size of that before the plague struck. Justinian’s son, Justin II, saw the Lombards occupy Italy, the Slavs take land throughout the Balkans, and the Avars settle on the Danube. From a rebounding Mediterranean civilization in the pre-plague period and the attempts to reconstitute the glory that was Rome in its heyday, within decades of the first Plague of Justinian the empire was shrinking toward a rump around Constantinople.
The Mediterranean region soon became a battle zone between Christians in the northwest and a new religion from the southeast—Islam. In 545 and 546, plague ripped through Mesopotamia, returning again and again to weaken the Persian Empire. Then in 569, Abyssinians fell back from the walls of Mecca thanks to pestilence.30 The Abyssinians were there, so the story goes, because an Arab chief from Mecca had defecated in a new cathedral constructed in Abyssinia. But their forces, led by an elephant, were met by the prayers of Mecca’s inhabitants. The elephant kneeled before the city while Allah sent birds each carrying stones the size of lentils to drop on the invaders. All sixty thousand struck were killed. This was in the year—perhaps even on the day—of the birth of the prophet Muhammad.
Islam survived and subsequently prospered in a largely plague-free Saudi peninsula after both Persia and the Roman Empire were crippled by plague. By 630 CE, Muhammad’s armies controlled all of Arabia, shutting off the sea route to the Indian Ocean. Within generations, the land route of the silk road would be closed, too. Exchange in silk, spices, and (probably) microbes all shrank back.31
The “Muslim quarantine,” although far from a complete halt to trading and exchange, helped keep Europe safe from renewed infection from the south and east. Forests spread between populated areas within Europe, slowing travel and further reducing trade. The greatly diminished movement of people within the former Roman Empire insulated populations against new and old diseases alike. Older people who had experienced earlier waves of plague and other infections (and lived to tell the tale) were immune. And circumstances were against diseases of density: the number of people in Europe declined from 70 million at the height of the Roman Empire to 25 million by 700 CE. Urban populations (the most favorable hosts for infection) shrank from half a million in Rome to twenty-five times smaller in the largest cities of 800.32
The remaining population was likely to have been better nourished and so more resistant to disease, the result of retreating to the most productive land for crops and using some of the rest for livestock. Justinian tried to freeze prices and wages, complaining that people had abandoned themselves to avarice, but the labor shortage gave farmworkers new leverage. The practice of using slaves on farms in Spain and Italy died out, replaced by the feudal system of serfs who owed loyalty and labor to a lord in return for land.33 And the Black Death disappeared.
* * *
Over the next centuries, lowered infection levels thanks to low population densities and restricted trade created the potential for renewed population growth in Europe. The weather also improved—enough for Britain to start producing wine (although chroniclers are silent on its quality). From the low point of the Dark Ages to 1300, populations tripled. Forests and pastures were converted back to cropland.34 Cities including Milan and Paris climbed toward two hundred thousand residents.
As the pestilences of the Roman Empire presaged the plague at its end, so did sickness and strife come before the hammer fall of the Black Death. For perhaps the first and only time in Northern European history, the Malthusian constraint of land availability threatened to become a major factor in determining death rates. The consequences of a bad growing season could be devastating. And when a series of bad seasons struck in a row, as they did from 1315 to 1322, deaths climbed into the hundreds of thousands across the continent.35
As early as 1316, reports John Kelly in his history of the period The Great Mortality, “as food grew costlier, people ate bird dung, family pets, mildewed wheat, corn and finally, in desperation, they ate one another.” Just as climate change may have helped create a weakened population toward the end of the Roman Empire, so it did in the fourteenth century.
And sources for continent-spanning epidemics were available once again, because long-distance trade had burgeoned. In 1206, the tribes of an obscure nomadic kingdom gathered at Karakorum in Mongolia to elect a new khan (leader). His name was Chinghiz, and he set his people on a road of conquest that, within two decades, left the great majority of the Eurasian landmass under their control. The Great Khan and his subordinates ruled territory from Eastern Europe to the Pacific, excluding only India, Arabia, and parts of Southeast Asia.
For all the fear generated by “a peril impending and palpably approaching” (as Pope Alexander IV put it in an appeal for Christian unity against the invaders), some Europeans saw the opportunities presented by the world’s newest and greatest superpower.36 In 1260, Niccolo and Maffeo Polo set off from the Venetian colony of Sudak on the Crimean peninsula to trade at the capital of Berke Khan, lord of the Western Tartars, to the north of the Caspian Sea. The Polos ended up at the court of his kinsman Kublai Khan in China.
Marco Polo, Niccolo’s son, accompanied his father on a return trip a few years later. He recounted the many quality goods produced along the route: the best goshawks in the world in Georgia, Persian steeds exported to India alongside the finest asses in the world, pearls pierced in Baghdad imported from India and sent on to Europe. He describes Tabriz: “a market for merchandise from India and Baghdad, from Mosul and Hormuz, and from many other places,” where Latin merchants came to buy merchandise. Hormuz itself was regularly visited by Indian merchants bringing spices, precious stones, elephant tusks, and cloth of silk and gold. And Kashgar was “the starting point from which many merchants set out to market their wares all over the world.”37
Seventy-five years later, the poet Petrarch was living in Venice and described the ships voyaging east:
“If you had s
een this vessel you would have said it was not a boat but a mountain swimming in the surface of the sea.… It is setting out for the river Don… as far as our ships can sail on the Black Sea, but many of those on board will disembark and journey on, not stopping until they have crossed the Ganges… then on to furthest China.38
There was so much to trade, and under the united control of the Mongol Empire, that trade was considerably more straightforward than previously when it had been necessary to work through the middlemen of the Middle East. As in Roman times the trade was unequal: while cloth and iron utensils went east, they weren’t nearly enough to pay for the silk, spices, skins, wood, salt, grain, and slaves that flowed west. The balance was made up in bullion.39
In passing, Marco Polo had mentioned something about the diet of herdsmen he met along his way: “They live on meat and milk and game and on Pharaoh’s rats, which are abundant everywhere in the steppes.”40 By Pharaoh’s rats, Polo probably meant marmots. The Tarbagan marmot can be an animal reservoir for the Black Death.
In his classic text Plagues and Peoples, historian William McNeill suggests that in the midst of a dry spell, herdsmen moved en masse into the northern steppe, where the Tarbagan marmot makes its home. This may have been the starting point of the Great Mortality—the return of the Black Death. By 1331, a mystery epidemic killed as many as nine out of ten in Hopei, Northeast China. The next year, the Great Khan Jijaghatu Toq Temur, ruler of Mongolia, died of a strange new illness along with his sons. By 1338, Kirgizia, in the northwest corner of China, was seeing an outbreak of pestilence recorded on thousands of gravestones of the afflicted.
We’ll see that McNeill’s version of events in East Asia is disputed. But eight years after the Kirgizia pestilence, Russian chroniclers report a plague arriving on the western shore of the Caspian Sea. And a year after that, it reached the Black Sea.
The Plague Cycle Page 4