Emperor Flavius Petrus Sabbatius Justinianus, otherwise known as Justinian the first, was not exactly the nicest man in Byzantium. Kindness and humility are rarely the first terms that spring to mind when we picture Roman emperors, but even in a crowd that includes such characters as Nero and Caligula, Justinian stands out as, frankly, an asshole. He also stands out as the man who came this close to being remembered as perhaps the greatest Roman emperor of all time. And when you're measuring out this close, put your fingers about two millimeters apart – just big enough to hold a flea.
Justinian's sixth century empire was not the Roman world of Augustus and Tacitus. Rome had been sacked by Alaric and his Visigoths in 410, and again by the Vandals in 455. The last remnants of imperial holdings in Gaul had been occupied by the Visigoths in 477, and by the time Justinian rose to power, the last man to style himself emperor of Rome (a 14 year old boy saddled with the title by his father, a military strongman) had been exiled from his seat for five decades.
Justinian's empire was the eastern empire, with its capital officially known as Constantinople, but often referred to by the more ancient name, Byzantium. He was born in the countryside of what is today Serbia to a peasant family without the centuries of patrician nobility that generally marked leadership in the empire. Justinian might have passed through history unnoticed, except that his uncle Justin – who had begun life as a poor soldier and risen through the ranks to become a wealthy general -- was childless and adopted Justinian as his heir. When the previous emperor died without a clear line of succession, Justin stepped into the role at age 70. Knowing that he lacked the political savvy to manage the empire, Justin turned to his more astute nephew for advice. Seven years later, in 527, Justinian was the Emperor of the Eastern Roman Empire.
This might have seemed enough of an accomplishment for a man who had come from obscurity, but Justinian's ambitions were far from slaked. He was so driven that he became known as "the emperor who never sleeps," and what he was driven to do was clear: restore the Roman Empire to the military and territorial position it had held centuries before it had been divided east and west. The empire he inherited was far from an insignificant domain. It spread over much of Turkey, Greece and the Balkans, down through Syria and Lebanon, and into Egypt. For Justinian, this was far from enough.
Together with his young Empress Theodora -- who caught Justinian's attention first because she was a very skilled as an exotic dancer (in the same sense as that term is generally used on roadside billboards today) and later because she proved at least his equal in wile and determination – the new emperor gathered what might be the biggest talent pool in history. Brilliant accountants who remodeled the tax system and provided Justinian new ways to squeeze the populace. Canny political advisors who helped the peasant kid from the sticks ferret out the most dangerous of his opponents among the city's noble families. The unmatched general Belisarius, who would prove to be both a tactical and strategic genius.
With Justinian at the reins, his political and military machine fortified the empire's eastern border, regained Rome's former holdings in North Africa, and marched into Italy. By 536, the city of Rome was again part of the empire. Justinian's armies ground out victories in Spain, captured Sicily and Sardinia, and restored the Adriatic as a Roman sea. The pope in Rome was recognized again as the true seat of Christianity (and the massive Hagia Sophia church built partly as a way to assuage hurt feelings in the east). Roman forces were fighting again in Tunsia, in Germany, and in outposts along the Black Sea. A visitor from three centuries before might have found the news comfortingly familiar.
To fund these operations, Justinian pressed the inhabitants of the empire harder and harder. Every aspect of life acquired new taxes and levies. He went beyond taxes and into what might better be termed a "protection racket" in which payments assured a lack of attention from his forces. He even forged wills for those who had been killed (sometimes at his order) in which they handed over their possessions to the empire as a show of their patriotism. By 541, Justinian's great successes had somewhat stalled as he maneuvered between renewed war in the east, internal dissent, and the unending need to find new sources of funding. Even so, he had grown the empire to the point where its boundaries were approaching those of Rome's glory days. The restoration of a united Roman Empire seemed not just possible, but nearly accomplished.
Justinian was far from shy about celebrating his accomplishments. His every movement through the city was attended by what in earlier times might have been considered a triumphal celebration, and if earlier emperors had been reminded that "all fame is fleeting," Justinian had no such whisperer.
But in 541, workers along the waterfront of Byzantium began to fall ill. Within a few weeks, the city was overwhelmed by deaths. In a city of perhaps half a million, five thousand people -- 1% of the population – were dying each day. Soon that would double and the unburied dead would line the streets of the capitol. Within weeks the plague had spread to the other cities of the empire, including its newly-captured ports and the outposts where the soldiers were gathered. Justinian himself came down with the illness, but recovered. He was lucky. Two thirds of those who exhibited symptoms were dead within a week.
By 542, one quarter of the empire's population had died, and in many areas the toll was much greater. The total mortality is hard to estimate, let alone grasp. It may have been 40 million, but it may have been twice that or more. In some areas, whole towns were simply obliterated. Survivors sometimes had to abandon regions that could no longer be sustained by those who remained. Despite the implementation of a very real "death taxes" (Justinian taxed every aspect of funerals, burials, inheritance, and settled many disputed estates through the simple measure of taking the wealth for the empire) the loss of population and the disruption of commerce cut off the gold needed to field troops on so many fronts. And on all sides, enemies saw opportunity.
The bid to restore Rome-that-was had ended. We can't be certain, but the most likely cause given the scope of the disaster and the description of symptoms is bubonic plague. Bubonic plague is a bacterial infection of the lymphatic system. The disease first makes its home in fleas. Eventually an infected flea can become so bloated by the bacteria that it is unable to process food and eventually dies. However, this gut-clogging has the perverse effect of making the flea ravenously hungry, so it spends its final days biting again and again in an attempt to take in nutrition. In the process the flea spreads the bacteria to everything it bites, including people. Those infected suffer chills and fever, along with the distinctive swellings of the lymph glands that give the disease its name ("bubo" is a Greek word for swollen glands). The disease likely spread about the empire along with rats (and their fleas) that hitched a ride in grain shipments. In any case, the disease spread quickly and attacked viciously across the extend of Justinian's territory.
Over the next decade, the resurgent empire gave up nearly all of the gains that had been made before the plague. When Justinian died in 565, the eastern empire still held onto much of Italy – though Rome had been reduced to fewer than 30,000 people wandering among the echoing streets that once held a million. With his death, even that token of the old expanse was lost. Even the nature of the eastern empire was radically altered. It became more insular, and began three centuries of slow decline. Justinian was the last emperor to speak Latin as his primary language, the last to really look on himself and his empire as Roman. From then on, the language of the east would be Greek, the language of the west would be as varied as the many tribes who occupied the lands of the former empire. Those squeezed by his ever-grinding desire for more income might have sighed in relief to see Justinian's wars of expansion ended and his reign over, but when he died the dream of Rome died with him. And it all turned on something as small as a flea, and on the much smaller bacteria that it carried.
Disease has shaped history more often than we usually credit. Not only did the possibility of Rome resurgent end with flea bites, the very same disease that helped usher in the Dark Ages might well be responsible for ending them. Outbreaks of bubonic plague continued over centuries, coming with the regularity of dark seasons across Europe, Africa, and Asia. Millions would die from bubonic plague in Italy, Spain and England as late as the 17th century, and millions more would perish in Russia from the same disease well into the 18th. But when we think of the disease, or even just the word "plague," there's really one outbreak that forms the center of that idea: the outbreak that began in the Crimea in 1346 and eventually spread across Europe, the outbreak that would eventually be named the "Black Death."
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The population of Europe had more than recovered the losses since Justinian's time and by the start of the Black Death probably topped 120 million. However, most of that population lived a grinding existence under a collection of ruthless monarchs. Even peasant doesn't really capture the nature of their lives. It was more closely akin to what we think of when we use the word "serf." They were tightly bound to small patches of land that they did not own, liable to hand over most of their produce to agents of the nobility, and subject to capricious "justice" that did not tolerate complains. As the population had grown, the rigid system and lack of additional arable land bore down on the workers, and as a result living standards had been dropping for the better part of a century. Peasants were seeing both their income and opportunities becoming even more restricted while kings, increasingly nervous about their own resources and threats from both within and without their borders, imposed ever tighter sanctions and steeper taxes. It didn't help that the 14th century brought a shift in the climate. Falling temperatures and changes in seasonal rainfall led to famine, disease, and high general mortality. If you think of the whole first half of the 14th century Europe as being shrouded in chill rain and despair, you wouldn't be too far off. Against this, the Black Death fell like the final somber notes of a dirge.
The Black Death began its macabre dance across Europe in 1346. Five years later, fully 50% of the population was dead. In many areas there were not enough left alive to bury the fallen. The cold rains poured down on abandoned villages and sluiced through neglected fields. It was a forsaken landscape. A place of skulls.
It was also the seeds of a much brighter day. In the wake of the Black Death, the balance of power shifted. So few workers remained that those healthy enough to till the land were a valuable commodity. They were able to demand better conditions from their lords, and able to find open ground to move to if they couldn't get what they wanted close to home. More emphasis was placed on better tools and innovative techniques. New ideas spread, and in fertile areas where the food supply was more than adequate to meet the reduced population, some workers turned toward the production of more valuable luxury goods. Trade in general became more expansive, peddlers developed into traders and shopkeepers. Craftsmen became artists. A mercantile class arose that was the beginning of the Middle Class, and within a very few years some of these former peasants and children of peasants were wealthy and powerful enough to directly challenge the rule of the nobility.
Only fifty years after the Black Death swept Europe, rival artists competed for the contract to build portions of the cathedral in Florence. It was the start of the Renaissance. Not all of the credit for the end of the Dark Ages is owed to the fleas that brought death across Europe, but neither were they wholly responsible for the start. However, bubonic plague contributed to enormous social, military, and economic changes that shaped our world.
Is it still a threat today? Yersinia pestis, the bacteria which causes bubonic plague, still leads to local outbreaks and deaths. The disease in endemic in many areas, and cases are annually diagnosed, even in the United States. However, for any number of reasons – antibiotics, improved sanitary conditions, rapid communication – these outbreaks rarely spread over a broad area. It's certainly possible that plague, paired with local instability and famine, can take thousands of lives, but it's highly unlikely that this disease will rise up again into a widespread epidemic (at least not so long as we maintain our current level of technical sophistication).
Of course, that doesn't mean we are safe from global pandemic. Each year, health organizations around the world keep careful watch on one of the most common of all diseases – seasonal flu. They do so with very good reason. Not only is the flu a demonstrated, regular killer whose annual passage around the globe takes hundreds of thousands of lives (41,000 in the United States alone), at points in the past particularly virulent and highly contagious forms of the disease have elevated this toll into the millions.
Flu is a viral disease. As viruses go, it's on the large size, but this is still an extremely tiny organism, little more than a spiky ball of RNA containing about 15,000 nucleotides. By comparison, the human genome has over 3 billion nucleotides. If the human genome were the Brandenburg Concertos, the flu would barely rate the opening chord. Simple as it is, Influenza shows a remarkable ability to "innovate" in the form of new subtypes. Bird flu, swine flu, and many others all fall within the versions of a single species. This propensity for spinning off new subtypes makes flu worthy of the attention health organizations and governments bring to bear.
After all, three times in just the last century pandemic flu swept the planet. In the outbreak that struck in 1918-1919 (originally called "Spanish flu" but likely to have originated either in the US or UK among the tightly packed troops training for World War I), somewhere between 50 and 100 million people died. It's possible that the 1918 flu killed more people than the Black Death did in the 14th century. It may have reduced the total world population by more than 5%, and it certainly brought with it a raft of changes, particularly in nations already weakened by years of war.
Flu remains a substantial threat, and if it sometimes seems that the government is too cautious in monitoring its variations or too anxious to introduce new subtypes into the annual flu vaccine, it's only because flu is such a proven killer. The threat of new flu pandemics is ever present, and the reason we haven't had another is simple enough: we watch for it and are willing to take swift action. If that no longer holds true, the chance of a global flu pandemic will rise from possible to near certainty.
But if flu is the devil we know, what about less familiar diseases? Lurking out there in the realm of bacteria and viruses are true horrors, diseases whose sources are poorly understood and whose effects are nightmarish. Among the most frightening are the viral hemorrhagic fevers. The list of organisms in this group reads like a who's who of malevolence. Hantavirus, which is acquired by breathing near the droppings left behind by rodents, causes symptoms that start off seeming like a bad case of the flu, but fever and aches are followed by plummeting blood pressure, irregular heartbeat, kidney failure, dehydration, and death. Hanta is endemic in several areas, including the western United States. Dengue fever follows one of the most common routes of infection, the bite of mosquitoes. Those infected can experience pain so severe that it gives dengue another name, "break-bone fever." Lassa fever was first described in Nigeria in 1969. It brings a racing heartbeat and stomach pains accompanied by bloody vomiting, and it causes about 5,000 deaths each year within a small region of Africa. Lassa was once considered the model for an "emerging disease" that was previously unknown, appeared without warning, displayed shocking virulence, and did not respond to treatment.
Frightening and deadly as these three are, just the name of some hemorrhagic fevers is enough to cause chills. In 1967, medical workers at a research lab in Germany were using vervet monkeys in an effort to create an improved polio vaccine. But it wasn't just the monkeys who became ill. Twenty-five of the workers developed debilitating fevers. In some the disease rapidly went further. A rash developed on their skins, then blood oozed from each raised bump. Then they bled from every opening of the body. Seven of them died as blood seeped from their organs and tissues. The disease was named for Marburg, the home town of the unfortunate researchers. Both in symptoms and in structure, it is closely related to another hemorrhagic fever: Ebola.
The actual number of people killed by Ebola and Marburg is relatively small when compared to other infectious diseases, but the fatality rate (up to 90% in the case of some strains of Ebola) and the horrific nature of the disease is enough to keep it high on the list of "things people do not want to catch." The disease generally crosses into human populations through close associations with other primates, but monkeys and apes are not the natural home to this virus. Ebola kills them as well, and it does so quickly enough that primates don't make a good reservoir for the disease. In fact Ebola has more than decimated populations of chimpanzees and gorillas in several locations, and is a much greater threat to those species than it is to ours. It now appears that Ebola and Marburg may be more at home in the systems of fruit bats, which can live with these viruses more or less unaffected. Fruit bats nibble on fruit that drops to the ground. Primates pick up the fallen fruit. People capture the primates for research (or, in many impoverished areas, for food). Then both people and surviving primates die. Messily.
Though these diseases feature prominently in fictional pandemics, so far the world has been spared a devastating outbreak of these hemorrhagic fevers. And no matter how many times you see Dustin Hoffman donning a space suit to chase down a snarling marmoset, that's probably the way it will remain. Though there are no standard treatments for many of these diseases, there are standard tests. With distinctive symptoms, a relatively brief period in which the infected person can pass along the disease, and protocol in place for identifying and isolating outbreaks, it's highly unlikely that you will ever hear of world capitals battling an outbreak of Lassa, Marburg, or Ebola.
If bubonic plague is now held in check, flu's annual rampage is limited through close observation and quick action, and even emerging diseases like Ebola don't present a threat that could reach T1 on our Teller Scale of Intolerably Large Disasters, is there nothing out there in the microscopic world that can pose a serious worldwide threat? In fact, there is. We have at least one modern model for a disease that can propagate widely, disrupt the progress of nations, upset markets, elicit social change, and kill millions, all while being closely (if often futilely) tracked by medical science. It's called AIDS.
AIDS was first recognized in 1981. Since then it has killed 25 million people and infected perhaps another 40 million. AIDS currently claims between 2 and 3 million lives a year, with a quarter of those being children. These numbers are dropping as inexpensive drugs become available in the worst affected regions, but it will be long time before they are less than horrific. Yet, relative to something like the flu, AIDS is a difficult disease to catch. You can't get it from being coughed on. It's not delivered to your bloodstream by an insect. It requires direct transfer of bodily fluids with an infected individual. Even so, and despite investment in programs of education and prevention, the infection rate in some countries of southern Africa exceeds 30% of the adult population.
Many factors have contributed to this spread including ignorance from political leaders and interference from social and religious organizations, but if there is one reason why AIDS has become such an enormous and sustained threat it's simply this: AIDS has an extremely long period between initial infection and onset of symptoms. That formula is a near perfect recipe for disaster.
A similar formula is at work in diseases brought on by the smallest of all infectious agents, prions. Prions are nothing but protein – no DNA or RNA involved. The difference between an infectious prion and a normal protein is purely structural; a physical difference in the way the molecule is folded. In a way that's not completely understood, introducing this odd form of protein into the body causes some of the normal protein to convert to this alternate form. Because this refolded protein can't be metabolized normally, it accumulates in certain regions of the body. In particular it can cause both hard "scales" and growing voids within the brain, a condition known as spongiform encephalopathy, literally sponge-like brain. The most famous of these conditions is one in which the prion first affects cattle, and later hits people who eat the cattle – Bovine Spongiform Encephalopathy, better known as Mad Cow Disease.
The modern appearance of Mad Cow began among cattle in the UK in 1984, but it was two years before anyone recognized it as a new disease, and longer still before all the infected animals were identified and removed from the system. So far, 165 people have died after coming down with symptoms that may have originated from eating meat from these cattle. Those symptoms being hallucinations, dementia, loss of coordination, tremors, memory loss, personality disorder, and just about every other terror you can imagine originating from a brain that is dissolving in place. That's 165 people so far. As many as 400,000 cattle carrying the prions for Mad Cow Disease may have entered the food system during the 1980s, and development of these disorders can be measured in decades. The real scope, and final death toll, of this epidemic is still unknown.
Like AIDS, spongiform encephalopathy isn't the easiest disease to acquire. It comes from eating the flesh of an organism already carrying the misshaped proteins, and the disease would not be a threat were it not for abominable practices within the cattle industry. Despite the difficulty of spreading the infection, the disease persists for the same reason that AIDS is a pandemic -- the long period between introduction of the infectious agent and the appearance of symptoms.
If we were to dream up (i.e. have a nightmare about) an organism that could spread around the world and cause a truly civilization threatening pandemic, it would be one that shared the devastating delayed consequences of Mad Cow or AIDS, but which was more readily transmitted through the air or by touch. Such a disease might spread across a large part of the population before it's even recognized. Such a disease may already exist.
There was a time when many medical researchers thought that infectious disease was on its way out as a threat to mankind. With bacterial infection on the run from antibiotics and the great viral scourges such as smallpox and polio halted by vaccine, they looked for a day when medicine would be more about repair than illness. But the microscopic world has proven more diverse and resilient than we expected. The specific names of the combatants may have changed, but the fight goes on. The global investment in fighting infectious disease is well deserved, because much more than asteroids, volcanoes or other threats we’ve considered, infectious disease has proven its ability to threaten great swaths of the world not just once, but multiple times, and it's done so within the relatively short span of history.
On our Teller Scale, the bubonic plague has certainly demonstrated its ability to approach or exceed level T2 – a threat to the existence of global or regional civilization. But the Black Death is not the worst example of disease impact on a culture. To see disease at its worst, we don't need to visit the 14th century Europe, we need to drop in on the turn of the 16th century. In America.
Until recently many historians reported the total population of the New World in 1500 to be only around 2-5 million people, about the population of England at the time. As it turns out, that appears to be something of an underestimate. The actual population of the Americas was probably at least 50 million, and may have exceeded 100 million – about the same size as all of Europe when contact between the two areas was made. Only instead of losing half its population to invading disease, Native Americans fell at a rate of 90% or more. Whole cultures – whole nations -- disappeared in the space of a season. When Tisquantum (better known as Squanto) returned from England and led the pilgrims to a good place to build their settlement, the site he selected was the ruins of his own village. Everyone he knew, his entire people, had died while he was away.
For the most part the Europeans moving into the American continent thought that they had discovered a nearly empty land with a few scattered bands of natives. They didn't realize they were building on top of graveyards, and fighting with the scarred survivors of what had been a much denser civilization only a few years before.
Because of the sheer size and diversity of mankind, it's unlikely that any single disease could ever eliminate us as a species. No virus is likely to reach T3 on the disaster scale. But the experience of the past teaches that they can come very, very close. These is no other threat in the natural world that deserves such careful and constant vigilance.