The 5 most devastating plagues in human history

There are currently over 100 million different types of viruses on our planet, but only several thousand types of these are capable of affecting humans. Most are only able to infect certain plants or animals or need specific conditions to live and pose no threat to us, and most of the ones that do can be easily treated with modern medicines. The bubonic plague is the most famous disease ever to infect the human race and rightly earns its place within the 5 most devastating plagues in human history, causing millions of deaths around the world, but anyone infected with it today would only need a quick injection to be cured.

Throughout most of history, this was not an option, and surviving an outbreak would be down to nothing more than luck. Here are the 5 most devastating plagues in human history and how likely people were to survive them.

The Justinian Plague – 541 – 549 AD

30 – 50 million dead

This plague spread across the Mediterranean region in 541 AD and was first recorded at the port of Pelisium in Egypt. The plague quickly spread across the whole region and was especially bad for the Sasanian and Byzantine Empires, with the capital city of Constantinople being hit very hard by the disease. It first arrived in the city on infected grain shipments from Egypt and managed to wipe out about 1/5th of the city’s population.

The plague was named after the Byzantine Emperor Justinian I who contracted the disease but managed to survive it during its peak year of 542. By 543 the plague had spread to all areas of the empire and countries surrounding the Mediterranean Sea but began to quickly die off starting in 545. After this, the plague moved further north and east but didn’t seem to cause the same amount of deaths in these areas until it finally died out in 549. Researchers have speculated that the disease was an earlier and slightly less evolved version of the bubonic plague, though this can’t be confirmed due to the time passed.

The Bubonic Plague – 1334 – 1353

75 to 200 million dead

The most famous plague in history and the most damaging to the human race. The Black Death as it is more commonly known, first entered Europe from the southeast and is believed to originate from either India or somewhere in the Middle East, though these theories can never be confirmed. It spread rapidly across the whole continent and wiped out an estimated 50% of the population of Europe.

(When someone died of the plague they were normally just buried outside the town or village without any records of it happening, which is the reason behind the huge range in total deaths)

The disease took around 2 weeks from the point of infection until death, and after someone was infected, they could spread the disease further through coughing and sneezing, though the original carriers were fleas. People initially thought that small animals spread the disease, primarily rats but dogs and cats were also suspected, leading to the majority of house pets being killed to try and stop the spread. This did little to stop the infected fleas and over a 19-year period, they managed to kill up to 75 million people in Europe and a further 100 million around the rest of the world, though records of deaths from the rest of the world don’t seem to have been kept.

The Columbian Exchange – 1492 – 1600

40 – 50 million dead

The Columbian Exchange was the name given to the mass transfer of plants and animals between Europe and the Americas. During the age of exploration, the Americas were seen as one giant money-producing machine, with new crops that could be mass-produced and sold for huge profits, and new land for the most powerful nations in the world to try and take for themselves. During this process, dozens of goods from the Americas were sent to Europe to help aid in food production, such as corn and the potato, but it also worked the other way, only with much more deadly effects.

(The Native American population was hit the hardest by the diseases because they didn’t have the chance to build natural immunities over the generations)

Because the Americas were so far away from Europe it took a long time for people to develop the boat technology to allow them to make the crossing, and this meant the Native Americans were left alone to develop without alterations to their genetics, or the chance to build up immunities to the various diseases that affected the rest of the world. The thousands of goods brought over from Europe to the Americas contained various diseases that the Europeans had built up partial immunity to, but the Native Americans didn’t have this chance and their populations were devastated by the new diseases brought over. Smallpox was the single biggest killer of them all, but other diseases included measles, diphtheria, typhoid, cholera, and the flu, all of which the native population was experiencing for the first time and had no immunities to.

The Third Plague outbreak – 1855 to 1960

12 – 15 million dead

This was the third major spread of the disease and the second most destructive outbreak of the bubonic plague, but this time it was mostly located around India and China. It caused an estimated 10 million deaths in India, 2 million in China, and between 1 and 5 million more in the surrounding countries. Like the other outbreaks of this disease, the point of origin is unknown but it’s believed the strain that caused the third outbreak evolved to live in hot climates and didn’t spread further around the world due to it naturally dying out in the colder or wetter environments.

Spanish Flu Pandemic – 1918 – 1920

50 – 100 million dead

This disease seemed to appear around the whole world at the same time, but due to it arriving right after the First World War, there was heavy censoring of the world’s press who were reluctant to report on a new pandemic. The first case of this disease was recorded in Kansas in March of 1918, but due to the censoring of public news, the world’s press rarely reported the first few cases in their countries, apart from Spain. This country stayed neutral during the war and its press were free to report on the many cases of this new disease within the country, and so the outbreak was associated with Spain.

The disease was actually influenza and within 2 years of the outbreak, it managed to infect a third of the world’s population, which was an estimated 500 million people. The most commonly agreed-upon figures when it comes to the death toll are between 17 and 50 million, but some sources put the number as high as 100 million. As with all major diseases in poor countries, when someone dies they are simply just buried without any official documentation, so we will never know the true number.