SARS-CoronaVirus-2, aka SARS-CoV-2, aka Coronavirus, aka Corona Virus Disease, AKA CoViD-19, is only the latest in a long list of pandemics to travel the Silk Road from Asia to Europe (and back again).
The biggest plague in recorded history, often referred to simply as “The Plague,” was the Black Death or Bubonic Plauge, caused by the yersinia pestis bacterium. Pestis killed over 200 million people, most of those during its famous European Tour between 1347-1353, but was actually still killing millions of people even in the early 20th century. The Third Pandemic, as the most recent outbreak is known, began in Yunnan, China in 1855, killed 10s of millions in China and India, spread to California (yersinia is now actually endemic to the fleas that infest prairie dogs in the American West,) and Africa, and was only declared over in 1960, when casualties dropped below 200 per year.
The bubonic plague ended because we can kill it with penicillin. The plague began in stone-age farming communities near the Black Sea, known as the Cucuteni-Trypillia culture, around 5500-2750BC. This was a lovely region with some of the world’s largest concentrations of humans and animals:
The majority of Cucuteni–Trypillia settlements consisted of high-density, small settlements (spaced 3 to 4 kilometres apart), concentrated mainly in the Siret, Prut and Dniester river valleys. During the Middle Trypillia phase (c. 4000 to 3500 BC), populations belonging to the Cucuteni–Trypillia culture built the largest settlements in Neolithic Europe, some of which contained as many as 3,000 structures and were possibly inhabited by 20,000 to 46,000 people. …
The culture thus extended northeast from the Danube river basin around the Iron Gates to the Black Sea and the Dnieper. It encompassed the central Carpathian Mountains as well as the plains, steppe and forest steppe on either side of the range. Its historical core lay around the middle to upper Dniester (the Podolian Upland). During the Atlantic and Subboreal climatic periods in which the culture flourished, Europe was at its warmest and moistest since the end of the last Ice Age, creating favorable conditions for agriculture in this region.
Their domesticated livestock consisted primarily of cattle, but included smaller numbers of pigs, sheep and goats. There is evidence, based on some of the surviving artistic depictions of animals from Cucuteni–Trypillia sites, that the ox was employed as a draft animal.
In short, the Cucuteni-Trypillia are the most important culture you’ve never heard of:
Although this culture’s settlements sometimes grew to become some of the largest on earth at the time (up to 15,000 people), there is no evidence yet discovered of large-scale labor specialization. Their settlements were designed with the houses connecting with one another in long rows that circled around the center of the community. …
Although trade was not likely necessary, archaeological evidence supports the theory that long-distance trade in fact did occur. One of the clearest signs of long-distance trade is the presence of imported flint tools found at Cucuteni-Trypillia settlements. …
Indeed, the Cucuteni-Trypillia saltworks located at the brackish spring at Lunca, Neamţ County, Romania, may very well be the oldest in the world. There is evidence to indicate that the production of this valuable commodity directly contributed to the rapid growth of the society. This saltworks was so productive that it supplied the needs of the entire region. For this to happen, the salt had to be transported, which may have marked the beginning of a trade network that developed into a more complex system over time. …
The Cucuteni-Trypillia people were exporting Miorcani type flint to the west even from their first appearance. The import of flint from Dobruja indicates an interaction with the Gumelniţa-Karanovo culture and Aldeni-Stoicani cultures to the south. Toward the end of the Cucuteni-Trypillia culture’s existence (from roughly 3000 B.C. to 2750 B.C.), copper traded from other societies (mostly from the Gumelniţa-Karanovo culture copper mines of the northeastern Balkan) began to appear throughout the region, and members of the Cucuteni-Trypillia culture began to acquire skills necessary to use it to create various items. Along with the raw copper ore, finished copper tools, hunting weapons and other artifacts were also brought in from other cultures. In exchange for the imported copper, the Cucuteni-Trypillia traders would export their finely crafted pottery and the high-quality flint that was to be found in their territory, which have been found in archaeological sites in distant lands.
The Cucuteni-Trypillia farmers lived on the edge of the Eurasian Steppe and interacted with the Yamnaya, nomadic herdsmen otherwise known as the Proto-Indo-Europeans. No one knows exactly why the PIEs decided to go on a rampage (perhaps a drought), but eventually they did, conquering (and probably absorbing) not only the Cucuteni-Trypillia, but also almost all of Europe, Iran, and India.
The important thing about the Cucuteni-Trypillia people is that there were a lot of them, living in close proximity to each other, with their animals.
Humans can live with animals, as the low-population density Mongols have traditionally done, without too much difficulty. Humans can live in enormous cities, like the 200,000 citizens of the Aztec capital of Tenochtitlan, without too many problems (well, other than the cannibalism and human sacrifice). But cram humans and animals together, and you get diseases. Add in trade routes, and you get pandemics.
In the year 1 (there was no year zero, despite what the graph says,) Rome was the capital of an empire with a population of almost 1.5 million people.
Between 169 and 180 AD, the Antonine Plague ravaged Rome, killing 2,000 people a day at its height. The Antonine Plague may have begun a few years earlier in China, but it was definitely brought back from the near east by soldiers returning from campaign. It spread across the Empire, killing approximately 5 million people. We think it was smallpox, but it might have been measles. Epidemiology wasn’t great in those days.
The Plague of Cyprian struck the Roman Empire between 249 and 262 AD; at its height, reports say that it killed 5,000 people a day in Rome. The effects of the plague can be seen clearly in the graph.
In 324, Constantine moved the capital of the Roman Empire to Constantinople (now Istanbul), ending Rome’s status as a major city for the next fifteen hundred years.
In 541, Yersinia Pestis made its first major debut with the Plague of Justinian, killing 25-50 million people in the Byzintine and Sasanian Empires. It most likely began in western China, was transported by nomads or merchants across central Eurasia, and then blasted through the civilized world.
Unfortunately, human complexity creates the conditions in which diseases breed.
Even without pandemics, the disease burden of early modern Europe was extremely high: most cities had grown much faster than their ability to dispose of waste and keep their inhabitants clean. The same trade networks that allow for the dispersal of new ideas and technologies (and what are technologies but ideas in action?) allow for the dispersal of pathogens. Indeed, their dispersal patterns are so similar that it is sensible to model ideas and diseases as the same thing, hence our much beloved “memes.”
Unfortunately, the spread of memes is now so rapid that humanity needs to stop and increase its technological ability to cope with the increased spread of disease.
Stay safe, stay clean, and stay healthy.