Ohio 7th Grade World History/Spread and Impact of the Black Death

Spread of the Plague


The Black Death was one of the deadliest diseases in human history. It killed 137 million in 3 major outbreaks. The 1st outbreak was called Plaque of Justice and occurred in 542 – 543 A.D where 70,000 people were killed in the city of Constantinople. The 2nd outbreak, the focus of this research, was the deadliest and is often referred to as the Black Death. It occurred in Asia and Europe, but mostly in Europe, where about 75 million Europeans were killed during the four years (1347–1351) of the plague. The spread of the Black Death was very dangerous. Italian traders first contracted the Black Death in trade with Asians. As these traders headed home, they carried the disease with them to trading ports in Italy. The disease followed traders and their cargo further west and north. By 1349 the disease had spread to all of modern Europe and its trading ports.

Spread of the Bubonic Plague Through Western Europe: 1346–1353

Rats, found on ships and on land, represented the primary pool of the disease, even though these animals themselves are immune to the bacteria that cause plague. The disease was transmitted to humans through flea bites where a flea would first bite an infected rat and thus, become infected as well. In a second step, the infected flea would transmit the plague bacteria to human hosts when piercing their skin to suck their blood.

Some forms of plague were also spread through air. If someone inhaled air that contained infected water droplets, they would catch the disease as well. People didn’t have enough knowledge about plague to understand that rats were a primary problem in relation to the disease. Instead of eliminating the rats, they fed them and gave them shelter.

Effects of the Bubonic Plague

The Triumph of Death an artwork non-literally depicting the chaos caused by the black death.

The Black Death caused many changes in Europe. The Black Death killed between 33% - 50% of the European population. Roughly 70% of the people who contracted the disease died. People assumed that burning the diseased bodies would help stop the disease from spreading. The catastrophic spread of plague is thought to have been facilitated by the general lack of hygiene and cleanliness back in the day. Streets were typically littered with garbage and dirt creating an ideal environment for rodents. In addition, the first wave of each large outbreak tended to show the highest mortality rate since few people were naturally immune to the disease. Subsequent waves were accompanied by increasingly lower death tolls due to a growing level of immunity among the existing population.

The effect the disease had on people's bodies were severe trembling, high fever and swollen lymphomas on their neck that turned black and often burst open. This was called bubonic plague. A person would usually die within 3 to 5 days. Another deadlier version of plague would spread through the air and often kill people in less than a day. This type is called pneumonic plague. At the height of an outbreak, the daily death rate would be so high that special carts were sent through the streets to collect the dead bodies.