Five thousand years ago, human settlements became large enough to support epidemic diseases. How many people lived in these settlements? It is estimated that the population needed to support a virus such as measles (after the first infection, a person has lifelong immunity to the disease) ranges from one million to 500 thousand people, and today up to 200 thousand people.
About 5,000 years ago, for the first time in history, epidemics appeared, traces of which can be found in human remains. The epic of Gilgamesh, about 4,000 years old, mentions the God of war and plague, ERRA. Egyptian papyri of the same period described a disease similar to smallpox . The mummies, which are 3,500 years old, have skin lesions resembling pockmarks. One of these preserved bodies belonged to Pharaoh Ramses V, who died suddenly in 1157 BC, when he was in his early thirties. From the ulcers on his dried remains, scientists have extracted a virus resembling smallpox — direct evidence that this disease appeared in Ancient Egypt.
New viruses that cause epidemic diseases came from animals. The smallpox virus is closely related to a virus that infects gerbils and camels in the Levant and North Africa. Camels were domesticated 5,000 years ago in the South of the Arabian Peninsula. The measles virus has diverged from the plague virus affecting cattle over the past 2,000 years, and in all likelihood it has happened more than once: a modern strain of the virus could be as young as 200 years old.
Pandemics have repeatedly changed the course of history. In 430 BC, the plague struck Athens at a time when the city was besieged by its constant rival Sparta. The epidemic, which lasted four years, claimed the lives of every fourth inhabitant of the city, including the ruler of Athens Pericles. Meanwhile, the Spartans were apparently immune to the disease. Some believe that it was the Spartans who brought the plague to Athens. Whatever the source of this first documented plague epidemic, historians believe it was the factor that accelerated the weakening of the influence of the Athenians and Greeks in General in the Eastern Mediterranean.
Soon the baton was taken by the Romans, also affected by the plague. In 166, Roman troops returning from the East brought a calamity to Rome that devastated the entire Empire. At its climax, the pandemic claimed the lives of five thousand Romans every day, killing one in ten of the Roman Empire.
And then there was malaria. Agricultural activities throughout the Mediterranean (cutting down trees, building roads, irrigation) created an endless habitat for the malarial mosquito adapted to humans, which carried the worst of the malarial parasites — the malarial Plasmodium (Plasmodium falciparum). By the year 100, malarial fever had devastated a densely populated area of the Pontic marshes South of Rome, on the Tyrrhenian sea coast. Malaria has not spared the city itself.
At the height of the Roman Empire, when Rome was a cosmopolitan city with a million inhabitants, a sewer system “big cloaca” and aqueducts that supplied clean drinking water, the Romans desperately suffered from malaria and other diseases. This can be determined by their physique. When the Romans settled in Central Europe, they were on average four centimeters below the local population. This difference in height had nothing to do with genes. After the collapse of the Roman Empire in the V century, the Romans became taller when they left the metropolis to feed off the land.
However, in the East, disease prevented the revival of the Empire. In the sixth century after the collapse of the Western Roman Empire, the Byzantine Emperor Justinian decided to seize the former Roman territory in North Africa. Justinian managed to do this, but then the plague struck his capital Constantinople, taking up to ten thousand lives a day. It took another 200 years before the epidemic went down (some thought it was smallpox, and others – bubonic plague). According to some estimates, about 100 million people had died by that time. At that time, the World population was about 190 million people. Had it not been for the Justinian plague, we could all have spoken languages derived from ancient Greek. And when nomadic armies left the Arabian Peninsula in the seventh century under the banner of newly minted monotheism, they might not have encountered old, decaying civilizations that had been ravaged by disease. Within a hundred years, the Islamic Caliphate had spread its influence from Iberia in the West across North Africa to the threshold of India in the East.
The higher the level of globalization and interconnectedness in human life, the more alarming epidemics were. In the thirteenth century, the Mongols created the largest Empire the world had ever seen. These famous horsemen ruled a vast part of Eurasia, stretching from the Pacific ocean in the East to the Danube river in the West. And in the midst of this stretch of land they have awakened a terrible calamity.
Carriers of plague stick (Yersinia pestis) — bacteria that cause bubonic plague-were burrowing rodents, marmots, who lived in the steppes of Central Asia. Fleas carried these bacteria, so people living near rodents, presumably having learned the hard way, imposed a strict ban on hunting these animals. However, the uninitiated knew nothing about it, and the new Empire attracted foreigners from all corners of Eurasia.
Records from outside Europe at the time do not allow us to determine exactly when and how the bubonic plague spread in Central Asia. However, it did happen. And in 1347 twelve Genoese sailing ships, just arrived from Kaffa (a trading port on The black sea coast), brought bubonic plague to Sicily. Early eyewitnesses describe nut-sized “burn blisters” in the armpits, neck and groin that oozed blood and swelled to the size of a goose egg. The agony usually lasted three days. Most infected people died. This terrible disease spread to the Mediterranean ports,and then inland. The townspeople fled, moving into the countryside, but the disease followed on their heels. Doctors tried to protect themselves with beak-like masks filled with spices, but still died. In 1353 the first (and heaviest) wave of “black death” finally went on decline. Taking into account the losses suffered during the subsequent waves, this epidemic claimed the lives of a third of the inhabitants of Europe, and maybe more. Moving along the trade routes that now covered the entire Eurasian continent, this epidemic has become a truly global pandemic.
It is estimated that diseases such as bubonic plague and smallpox have killed more people in human history than all other infectious diseases combined. These two diseases have held back population growth for a Millennium. Of course, as Jared diamond elaborately argues in his book Guns, Germs and Steel, this epidemic itself has become a valuable asset, an accidental tool of biological warfare that Europeans unleashed on both American continents in the late seventeenth century. After the first contact with Europeans, the number of American Indians in just a few decades decreased to one tenth of their original huge number. With nothing comparable to the contamination of Eurasian civilizations in a sense, ensured their ultimate victory.