Wallowing toward ruin when births exceeded resources and the first pandemics

In the late Roman era, nature produced a cruel cure for the new diseases of urban life

During the late Roman era, all over Europe, Asia, and North Africa; there were too many people who were too densely crowded.

The creation of farms, roads, and cities disrupted the environment; diseases traveled with lethal effect among the once distinct disease pools of Europe, Africa, India, and China.

New technology had allowed populations to explode, but it offered no cures for the resulting epidemics. Eventually, spasms of pestilence brought a worldwide population crash that seemed to threaten humans with extinction.

To some modern biologists, such mass die-offs seem to be natural events; but until rather recently, the usual explanation for the first pandemics was not biological; however, it was thought that the immoral lives of people resulted in a supernatural punishment for their sins.

Religious leaders preached that sin, selfishness, and paganism were the reasons people saw their families and neighbors dying each day. This appealed to a deeply rooted human tendency to see illness as punishment and the plague as a divine vengeance.

From the ancient Hittites and Hebrews to the villagers of Pudoc and Americans with sexually transmitted diseases, epidemics have roused fits of guilt and, sometimes literally, self-flagellation.

The early Christian claim persisted that Rome had wallowed its way to ruin

When Edward Gibbon wrote his well-known History of the Decline and Fall of the Roman Empire in the late eighteenth century, he polished the old image of pagan decadence luring humanity down the slope to social and physical destruction.

This alleged lesson of Rome to posterity has been applied to many times and places: sex, selfishness, and prosperity itself are said to be agents of spiritual and bodily degeneration, and finally of death.

Rome's fall was not caused by over indulgence of food and and sensuality, but by nature's response to overpopulation and ecological changes.

In 1798, a cleric and economist by the name of Thomas Malthus produced An Essay on the Principle of Population, in which he argued that unchecked population growth tends to outstrip gains in food and other vital resources.

When there is not enough food, the birth rate falls and the death rate rises because of overcrowding, poverty, famine, war, and finally disease, as "sickly seasons, epidemics, pestilence, and finally disease, as "sickly seasons, epidemics, pestilence, and plague advance in terrific array, and sweep off their thousands and tens of thousands." Millions would have been more accurate.

The Roman Empire's big cities were not hopelessly unhealthy

Rome and some provincial capitals had extensive water and sewage systems, flush toilets, public baths, and food inspections.

Their size and wealth made ancient Babylon and Nineveh seem paltry, and their better-off citizens lived a decade longer than had their Paleolithic forebears.

Yet all the triumphs of food production, engineering, and sanitation could not prevent epidemics that made the population level off and start to decline.

For several centuries, the empire was undermined by conflict and chaos, and depopulated by waves of new diseases. Some came from other species, as they always had, but some also came from other empires.

Before Roman times, infections from distant ecosystems had struck the West occasionally; the first recorded instance was the plague of Athens, in 430 B.C. Only thirty-five years later, the Roman world suffered a similar epidemic.

It, too, came from North Africa by ship during a war, when Carthaginians besieged the sicilian city of Syracuse. The epidemic took so many lives that almost five centuries later, Livy described it as one of the eleven major plagues that Rome had suffered since its founding.

A disease, native to Africa's rain forests, had traveled down the Nile to the Mediterranean, then spread east to the Mesopotamian Fertile Crescent and north to Greece

Greek traders and colonists eventually carried it to Italy. Roman soldiers and merchants would help several forms of malaria move as far north as England and Denmark.

For 2,000 years, where ever Europe had human crowds, new forts and settlements, domesticated animals, and standing water where mosquitoes could breed, malaria would flourish.

It left people weak, apathetic, and short-lived; and it may have contributed as much to Rome's fall as any other epidemic that followed it.

From the second century on, new diseases appeared in Europe with greater frequency and devastation. Rome's empire now touched India and the steppes leading to Mongolia and China.

Western seamen had found routes across the Indian Ocean to the South China Sea, and they traded directly with the Han court in imperial China.

Their ships could carry infected men, insects, rodents, and cargo; pathogens could breed in their water and provisions. There was East-West contact also through caravans along the Silk Road; where the Chinese exported raw silk to the Roman province of Syria, where it was rewoven and traded westward.

Trade by land and sea therefore connected people from the Atlantic to the Pacific, and could carry diseases traveling both east and west.

Just as important in spreading diseases were the Huns. Late in the first century A.D., these ferocious nomads came riding out of their homeland northwest of China. For centuries, waves of displaced people, followed by conquering Huns, would bring wars and epidemics to the Roman world, eroding its borders and thinning its ranks.

In the fourth century, the Roman empire had split in half, with capitals in Rome and Constantinople

In the next century, Rome was sacked by Goths and Vandals; the western empire crashed before the century ended. The eastern realm survived; as the middle of the sixth century neared, the eastern emperor, Justinian, was reconquering western territories from German tribes.

By 542, Justinian had taken back much of North Africa, Sicily, and part of Spain, and was poised to go after more; then came the plague!

While the word "plague" is used for any severe epidemic, what hit Constantinople was not a plague, it was the plague, bubonic, which in a later outbreak would be called the "Black Death".

The pandemic of Justinian's reign was no doubt bubonic plague and it caused one of the worst die-offs in human history.

The sickness started with fever. On the first or second day, buboes, or "swollen lymph glands", appeared in the armpits, groin, and neck. Fever raged, agonizing buboes swelled, and the germ assaulted the nervous system, causing lethargy or hallucinations.

Half or more of those infected died by the fifth day. When cold weather arrived, the disease changed to its pneumonic form, which was spread by coughing and destroyed the lungs. People died vomiting blood and choking on it. Pneumonic plague was; and without antibiotics still is, fatal to 95 percent of its victims.

Panic, disorder, and murder reigned in the streets of Constantinople. There were too many corpses to bury. The roofs were removed from the city's fortified towers, and bodies were stacked in them like cordwood. Soon the towers were full, and the stench became unbearable.

People kept dying, up to 10,000 each day, and there was no place to put the dead bodies. Rafts were loaded with the dead, rowed out to sea, and set adrift. When this bout of plague ended, 40% of the city's people had died.

The plague spread rapidly to coastal cities all over the Mediterranean and traveled more slowly inland. For six straight years, it devastated Italy, Spain, France, the Rhine valley, Britain, and Denmark.

Justinian's attempt to restore the western empire collapsed. Europe's agriculture ebbed, and trade almost halted. Many cities became, like Rome, scourged remnants, with the dead heaped in the streets and the living huddled in churches praying for deliverance.

When the first pandemic receded, Europe felt it had been reprieved from death. So did much for the rest of the world, from North Africa to Japan. Europe's population had been cut in half, and city life virtually ended.

Cured, for the moment, of diseases bred by urban growth, Europe could recuperate. That required a centuries-long rest which would be called the Dark Ages.

Part 4 of 4.