top of page

Plague, Pestilence, and the Pandemics of History

How Disease Has Changed Civilization

By Brendan Wilson

In the "before time", prior to January 2020, we lived secure, carefree lives.  Our biggest macro-level fears were climate change and Kim Jung Un blanketing the western United States in hellfire.  But let's face it, it was difficult for the average person to see the terror in a single degree rise in oceanic temperatures or the threat posed by a plump Asian dictator with a weird bowl cut.  This delightful illusion of security was upended in February, when reports of a deadly respiratory virus began to leak out of China.  Curiosity turned to fear as the world’s interconnected supply chains, international travel, and open borders transformed into super highways that would bring a deadly virus to our doorsteps.

Today, over 26 million people have been infected with Covid-19, leaving nearly 1 million dead. We all ask questions for which we know there are no definite answers: when will a viable vaccine be available?  Is my layoff temporary?  Will there be a deadly second wave?  The only certainty is that this pandemic, like all of history’s pandemics, will create dramatic, lasting changes to our society.  For this reason, it’s instructive to look back on some of the pivotal pandemics of history and the legacies they left.  

Plague of Justinian

Named for the Roman Emperor Justinian I, The Plague of Justinian was a bubonic plague that emerged around 561 C.E. and ravaged Europe and Asia for 200 years, killing between 25 to 100 million people.  The disease was caused by the bacterium Yersinia Pestis, which lived in fleas carried by the Black Rat.  Symptoms included fever, headaches, swelling of lymph nodes, and blackened skin.  Some suffered for days while others died within hours of the first symptoms. The dead were piled high in the streets, creating an unbearable stench that permeated towns and served as horrifying reminders that death always lurked just around the corner.

6th century Rome was split into the West, ruled by the Ostragoths, and the East, ruled by Justinian in Constantinople.  Intent on reunification, Justinian deployed armies to reclaim the western half.  Also during this time, the climate cooled dramatically, leading to poor harvest yields that left much of Europe's population malnourished.  In The Fate of Rome, Kyle Harper argues that these two conditions combined to render people particularly vulnerable to a deadly pandemic.   As Patrick Wynman eloquently phrased it, “three of the four horsemen” of the apocalypse rode together, spreading war, famine, and plague all over the continent.

The plague struck at a critical moment in Europe's history, forever changing its course.  Some historians credit the apocalyptic conditions with the rapid spread of Christianity throughout Europe.  Economically, it decimated the port cities of the Mediterranean and, with so many consumers dead, diminished demand for traded goods.  This led to a precipitous fall in global trade.  Most importantly, a hemorrhaging war chest and dying soldiers forced Justinian to recall him armies, weakening Roman territory in both the Eastern and Western parts of the Empire.  As a result, Persians claimed territory in Egypt and Asian Minor, Goths reclaimed Rome, and the Lombards invaded northern Italy.  Not only would Rome fail to reunify, it would fall. 

Black Death

The bubonic plague was not finished with Europe.  In the 14th century, it rose again in China and entered Europe through Sicily in 1341 by way of Mongolian hoards and merchant ships.  It killed an estimated 25-30 million people over four years.  Yersinia Pestis was again the culprit, relying on rats to swiftly spread the disease to nearly all corners of the continent.  Cemeteries once more overflowed, forcing the dead to pile up in the streets.  The shock was so significant that England and France called a truce in the infamous Hundred Years War.


As with the Plague of Justinian, several key developments combined to enhance the effectiveness of the disease.  First, Mongol hoards swept with terrifying speed from Asian to Europe, leaving a trail of carnage and disease in their wake.  In one harrowing instance, while laying siege to the Crimean city of Caffa, they catapulted plague ridden corpses over city walls.  Second, the “little ice age” one again cooled the climate, devastating harvest yields and rendering a malnourished population physically unfit to fight off the disease.  Finally, Venetian and Genoese trade ships carried rats from port to port, delivering their deadly cargoes to the ill-fated dwellers of the cities they visited.

The legacy of the Black Death is well documented.  In his book, The Great Leveler, Walter Schiedel explains that the decimated peasant populations significantly increased the bargaining power of the few laborers that remained.  This shift in the balance of power caused the breakdown of serfdom, eventually unbounding the serfs from their land-owning noblemen.  Peasant uprisings in the second half the 14th century in Paris, London, and Florence are further evidence of this shift.  Additionally, on account of all the dead men, women enjoyed the right to own property that they did not have prior to the plague. Finally, the question “how could a just God allow this to happen” greatly diminished the credibility and power of the church, raising doubt in traditional authority that would help sow the seeds for Europe’s renaissance. 

Spanish Flu

It is widely agreed that the Spanish Flu was the deadliest of history’s pandemics.  An estimated 50 million people, or nearly 5% of the world's population, were wiped out by the disease in a single year.  The first cases of the virus were reported in the United States and quickly spread to Europe, carried by the millions of soldiers deploying to WWI’s front lines.  Its symptoms were fevers, headaches, chills, and aches.  Paradoxically, the virus was most deadly for the young and healthy, turning a strong immune system against itself.  Surgeon Harvey Cushing labeled these victims “doubly dead”, as they were killed before fully living life.

Troop movements were again to blame for rapid transmission.  Unprecedented demand for war materiel mobilized millions to urban factory centers, clustering multiple families in rickety tenement buildings and leading to population density unseen in human history.  American scientists, understanding that they were dealing with an air born pathogen, recommended the cancellation of large, public events.  This advice went unheeded with devastating effects, most notably when Philadelphia’s mayor refused to cancel a parade that would gather 200,000 city residents. Philadelphia would become America’s hardest hit city, with as many as 4,000 people dying in a single day.

The pandemic had many lasting impacts.  Many historians attribute the defeat of Germany and Austria to their higher mortality rates, arguing that the disease turned the tide in the war.  After WWI, empires fractured into nation states.  The threat of the pandemic hardened the borders of these newly formed nations, leading to travel restrictions that required previously unnecessary documentation like passports.  This nationalism laid the groundwork for the most devastating military conflict in human history.


On March 11, the WHO declared Covid-19 a pandemic. As with the previous examples , the pandemic's effects are so traumatic that our society will be forever changed. Below are some of the ways that we can expect this terrible disease to transform the way we live:

  • The way that we work will change.  Remote work policies have spurred the board room realization that companies can save millions in long term rent by doing away with expensive campuses and entire floors in desirable city centers.  Commercial real estate and the small businesses that depend on city traffic will suffer terribly.

  • Hard borders and strong governments will rise. In his WSJ essay, A World of Hardening Borders, Yaroslav Trofimov laments the reemergence of the nationalism that arose in Europe after the Spanish Flu.  Governments close borders and dramatically expand their powers to surveil their citizens and shut down businesses, evoking the actions taken by governments in the early 20th century.

  • International trade will experience a lasting drop off.  Many countries found themselves exposed by their foreign supply chains.  Bret Swango of Colliers International sums it up well, “Governmental entities are keenly concerned about reshoring the production of components critical to national security including personal protective equipment, medical devices, pharmaceuticals and products relied upon for national defense”. As with the pandemics that came before it, Covid-19 will severely damage global trade.

  • Peak international travel may be behind us.  The UNWTO estimates that 2020 International travel could be down 60-80%.  National travel restrictions combined with a leeriness to climb into a flying sardine can and share recycled air with 300 potentially disease-ridden passengers could delay the industry’s full recovery for years.

Source: United Nations World Tourism Organization
Source: United Nations World Tourism Organization

In our daily slog through life, we often miss the forest for the trees.  It is difficult for us to see that we are living during a moment in history that will be closely studied generations in the future.

Barry, J. M. (2018). The great influenza: The story of the deadliest pandemic in history. NY, NY: Penguin Books.

Cartwright, M. (2020, August 31). Black Death. Retrieved September 05, 2020, from

COVID-19: The Great Accelerator of Onshoring (Part 1). (2020, July 28). Retrieved September 05, 2020, from

Harper, K. (2019). The fate of Rome: Climate, disease, and the end of an empire. Princeton: Princeton University Press.

Horgan, J. (2020, September 02). Justinian's Plague (541-542 CE). Retrieved September 05, 2020, from

SCHEIDEL, W. (2018). GREAT LEVELER: Violence and the history of inequality from the stone age to the twenty ...-first century. Place of publication not identified: PRINCETON University PRES.

Seib, G. (2020, April 27). Coronavirus Strengthens Nationalist Currents. Retrieved September 05, 2020, from

Trofimov, Y. (2020, April 17). A World of Hardening Borders. Retrieved September 05, 2020, from

WORLD TOURISM ORGANIZATION. (2019, June 28). Retrieved September 05, 2020, from


bottom of page