Spread the Word, but Cover Your Mouth

We like to think that more connection is good. However, more people interacting can also cause problems. Diseases are a key example.

For example, the Internet connects billions of us worldwide. Our connections help us to communicate. However, they also put us in a new kind of danger. More computers mean viruses can hurt us in minutes.

One of the worst viruses ever was the Conficker worm. In 2008, it quickly took over 30 million computers. The worm disrupted many governments and businesses.

The Internet of the 1300s was the Silk Road. It linked China to Europe. However, this wasn’t a single road. It was a network of trade. It connected merchants, cities, trading posts, and paths. And like the networked Internet, ideas, information, goods, and money all traveled along the Silk Network. But these long-distance trade connections also allowed diseases to spread farther and faster than ever before. This is not unlike computer viruses of today, except more deadly. The worst of these was an outbreak of bubonic plague. It happened in the 1300s. This deadly disease was also called the Black Death.

The Black Death was not the only plague to spread along trade routes. Diseases have joined humans since we started crowding into cities and came into contact with faraway peoples, and their animals. But how did this particular plague get to be so bad? Interestingly, it began in a time of peace.

The Pax Mongolica

The Pax Mongolica was a period from the mid-1200s to the mid-1300s. “Pax Mongolica” means Mongol Peace in Latin. By this time the Mongol Empire had split into four areas. Each was ruled by a “khan.” The Mongol Khans connected much of Eurasia’s people.

The earlier Mongol conquests disrupted trade routes with their violence. That was the period when the Mongols built their huge empire. But during “Pax Mongolica” there was little war. This was unusual. It allowed more trade connections to develop all across Africa, Europe, and Asia. This landmass is also known as Afro-Eurasia.

The Mongol Khans carefully tried to govern their huge empire. They grew more concerned about earning tax money. Much of that came from trade. So, the Mongol Khans worked hard to make trade easier and safer. Trade networks and business grew. But the flowering of trade connections also carried the seeds of disaster.

Yersinia pestis: The Black Death

The spread of Black Death was caused by the Yersinia pestis bacterium. These bacteria sometimes spread to humans. First, they must touch the fluids of an infected person. More commonly, though, it is spread by flea bites. Before feeding, fleas vomit into our bloodstreams. This is how the bacteria spread. The effects of the bubonic plague are just as gross. Soon after infection, the diseased person develops swelling in their body, called buboes. Next, bleeding inside the body causes swellings of pus and blood. This gives the skin strange colors. It was a horrific disease. Bubonic plague spread quickly and without warning. Most people who got the plague died.

Merchants of death: A trade plague

The Black Death spread along trade networks. Human interaction with animals and the environment also caused its spread. Take for example Central Asia. It is the region west of China and south of Russia. The fleas there that carried the bacteria lived on rodents known as great gerbils. Just a small temperature increase can boost the presence of the bacteria in the gerbils by up to 50 percent. The climate also seemed to change in the middle of the 1300s. This, too, likely helped the disease to spread out from Central Asia.

Yersinia pestis got its start in Central Asia’s countryside. The disease spread through flea bites. But the fleas escaped from Central Asia. They spread on the backs of traders and camels traveling in caravans. From there, the fleas attached themselves to rodents traveling with the caravans. Plague also spread with rats in trading ships. Soon ships carrying plague rats and merchants arrived in other trading ports.

Then the plague spread like wildfire. It likely arrived in the Mediterranean onboard Italian merchant ships. The Pax Mongolica made the Italian city-states super-wealthy and powerful. Venice and Genoa were just a few. During this period Marco Polo of Venice traveled through the Mongol Empire. Other Italian merchants traveled east. They bought luxuries in Indian ports like Calicut. The unifying rule of the Mongol Empire made these new kinds of meetings possible. But it also meant more plague. After people met, they brought plague-infected rats back to distant lands. The Black Death would not have been so deadly or so widespread without the Mongol Empire’s trade networks.

A specter haunting Eurasia

As many as 100 million people across Afro-Eurasia might have died from the Black Death. That was a huge number. Compared with today’s population, it is equal to between 1 billion and 2 billion people dying.

After the plague, trade declined everywhere.

Europe got hit the worst. Its cities were crowded, damp, and dirty. The plague decimated Europe from 1347 to 1351. It killed up to 25 million Europeans out of a population of 75 million. In some Italian cities and France’s countryside, however, death rates approached 60 percent. Europeans tried to make sense of the death and terror brought by the plague. Many thought that the world was ending. Others began to question the power of the Catholic Church and the social class system around them. Peasant uprisings increased. In many places, angry mobs attacked Jewish communities. They wanted someone to blame for their troubles.

Death and labor: Plague reshapes European economies

Still, the horrors of Black Death were followed by some positive changes. The sudden death of millions of people completely changed social relationships. The transformations caused by the Black Death might have brought an end to feudalism. They also likely helped to start the Renaissance in Europe.

Fewer people meant fewer peasants to work the fields of feudal lords. Feudalism was how European societies were structured at the time. Poor workers had little power. After the plague, though, workers who didn’t die gained power. Soon, workers everywhere started to demand higher pay. Pay in England, for example, rose as much as 40 percent between 1340 and 1360. Europeans who survived the plague lived longer.

Higher earnings created a middle class in Europe that could buy more products. And with fewer workers in the fields, people had to get creative. Landowners started to raise more livestock. Raising animals took less labor than growing wheat. It also inspired technological growth in farming. New plows forever changed European farming and saved labor.

The rise of a middle class, especially in Northwest Europe, helped to jolt business and reestablish trade networks. With higher wages, more workers could pay for goods that had once been considered to be luxuries. Slowly, European businesses bounced back. But the cultural and social changes were there to stay.