Unseen menaces have affected human society ever since humans have gathered. As more people have come together, the dangers of viruses and expansion of sickness grew. Illnesses have wiped out everything from entire villages to societies, morphing and altering world history. Below we will site some of the ten most deadly pandemics and epidemics in history.

We have cobbled together a number of different sources for this project and have done our best to average and then place the events in the most known and deadliest order. Due to the nature of pandemics and epidemics throughout history, it is, quite naturally, difficult to obtain accurate numbers for this project.

Before we go further, we will note that COVID-19/the Chinese Virus will not be included due to the incredible amount of misinformation published and its numbers are inherently unreliable due to discredited source material. If it were included and we did use the source material, it would likely rank as fifth in this list.

10 & 11. 1957-58 Influenza Pandemic & the Hong Kong Flu

Type: 1957-58 Influenza Pandemic: A/H2N2

Type: Hong Kong Flu: A/H3N2

Origin: 1957-58 Influenza Pandemic: Guizhou, China

Origin: Hong Kong Flu: Descended from H2N2; Originated in Hong Kong but potentially from within China in Guangdong province or southeastern China; other locations possibly within China.

Deaths: 1957-58 Influenza Pandemic: 1-4 Million

Deaths: Hong Kong Flu: 1-4 Million

1957-58 Influenza Pandemic

The Influenza Pandemic of 1957-58 was first noted in Singapore in February of 1957 followed by Hong Kong in 1957 and a number of other coastal cities. By the summer of the same year it had crossed the ocean and into the United States. While the CDC claims the number of deaths at 1.1 million, estimates do range as high as 4 million.

Hong Kong Flu

Potentially latching on from the aforementioned virus, the Hong Kong Flu likely originated within China. While by some sources it wasn’t as deadly as the 1957-58 Influenza Pandemic, it was certainly more contagious. As it broke out in 1968, it easily crossed the ocean with American soldiers returning home from Vietnam and the virus continued to spread throughout the world. There were two waves of the virus, the second being much more dangerous. While many sources cite the death toll at roughly 1 million, as with the 1957-58 Influenza Pandemic, some sources range as high as 4 million.

9. 1918-1922 Russia Typhus Epidemic

Type: Typhus

Origin: Eastern Europe but potentially began in Serbia

Deaths: 2-3 Million

The Eastern Front was truly the catalyst for this epidemic as lack of hygiene in war helped to spread typhus through the ranks, particularly in Russia. During World War I there was a common saying among opposing soldiers that it was more dangerous to shake a Russian soldier’s hand than it was to be shot at by him. On top of World War I, the Russian Civil War and the Typhus Epidemic, Russian demographics took an incredible hit and would stunt the nation’s potential. This bout of Typhus settled in Russia, killing between 2-3 million of its people out of the 20-30 million cases.

8. 1520 Mexico Smallpox Epidemic

Type: Smallpox

Origin: Mexico

Deaths: 5-8 Million

European discovery and expansion into the New World brought many things from soldiers, to ideas to disease. The 1520 Smallpox Epidemic in Mexico was one such devastating thing which set up the eventual Spanish conquering of the region and proclaiming its ownership over much of the landmass. It is estimated that by 1576, up to 17 million people had died. However, numbers of native tribes of America are difficult to come by due to the unknown interior and lack of records. For that reason, these numbers could fluctuate quite a bit higher and the years could last much longer but in this instance we’ve taken a known case from an observable point.

7. Antonine Plague

Type: Smallpox or Measles

Origin: Possibly Seleucia in Mesopotamia

Deaths: 5-10 Million

While this plague had likely begun in Rome’s Near East, the Roman soldiers brought it home with them and it spread through Europe between 165-180 AD. While supposed to be smallpox, there are claims by some historians that it was in fact measles. Either way, the disease ran rampant throughout the Roman Empire claiming between 5-10 million lives, ravishing everyone from the poor all the way up to potentially killing the Roman emperor, Lucius Verus. While this bout of the Plague ended in 180 AD, Cassius Dio notes that the another outbreak occurred nine years later in Rome. The Antonine Plague killed roughly 10% of the population within the Roman Empire.

6. Third Plague Pandemic

Type: Bubonic Plague

Origin: Yunnan, China

Deaths: 12-15 Million

The Third Plague Pandemic exploded out of China in the late 1850s, pushing the bubonic plague around the world. A rush of Han Chinese flooded into the Yunnan area to exploit the minerals there and the population boomed to over 7 million. This population combined with the deadly bubonic plague helped to spread it dangerously and quickly. However, most of the deaths occurred in British Raj India at roughly 10 million and likely 12 million total between India and China with a potential world wide number total of 15 million deaths. The WHO claims that the pandemic was considered “active until 1960”, over 100 years after its boom.

5. Cocoliztli Epidemic

Type: Unidentified

Origin: Mexico

Deaths: 5-15 Million

This covers a series of epidemics which had the most devastating effects in the Mexican highlands. Contrary to the 1520 Mexico Smallpox Epidemic, this epidemic often occurred within two years of a drought season. Ranging from the periodic years of 1545 to 1813, people would often suffer from hemorrhagic fevers obtained from rodents who showed up during the rains which followed the dangerous droughts. However, this wasn’t contained to only Mexico as these same claims came from as far south as Venezuela and as far north as modern Canada. It seems the native tribes were most affected but both natives and Europeans were struck down in horrible amounts. While the death tolls do range from 5-15 million, the average of the numbers often range higher and due to limitations of knowledge, could surely exceed this number.

4. HIV/AIDS

Type: HIV/AIDS

Origin: Central Africa

Deaths: 35-48 Million

While the WHO claims that roughly 40.1 Million people have died from HIV/AIDS, numbers vary wildly from 27 million to 48 million, however, most fall within the mid to high 30 million range. Created sometime around the late 19th or early 20th century, HIV originated in primates before mutating and jumping to humans numerous times. The disease spread quickly through prostitutes, gay men and those who injected drugs. HIV had reached a dangerous level noted in 1981 and continues to be a problem today. While it has become more manageable in Western countries to the point that there are many millions more of confirmed cases, it remains an incredible danger throughout the continent of origin: Africa.

3. Plague of Justinian

Type: Bubonic Plague

Origin: Mediterranean Region: Perhaps Lower Egypt

Deaths: 30-100 Million

Death tolls range wildly from 15-100 million, however, most average out at the higher end with many consistent lows at 50 million. The Plague is named after the Byzantine Emperor of the time, Justinian who had contracted the disease but ultimately overcame it. While it likely originated from outside of his Empire, it had ravaged the capital of Byzantium, claiming many millions of lives. However, the disease didn’t persist solely in Byzantium during this time. Instead, it traveled around the eastern sea, hitting each location between 541-549 AD. Modern researchers have noted that the strain is likely the same as that of the Black Death which would show up roughly 800 years later and that this strain had ultimately come from mountain ranges along Kazakhstan, Kyrgyzstan and China. This is the first known outbreak of a Plague Pandemic of this sort as a third of Europe’s population had been killed and at its height, roughly 5,000-10,000 people a day were dying in Constantinople alone. While the plague had continued beyond these years, the most dangerous of it seemed to have ended by 590 AD.

2. Spanish Flu

Type: Influenza A/H1N1

Origin: Unknown

Deaths: 25-100 Million

Due to World War I and media blackouts, pinning down the first case of the Spanish Flu and its origin remains unknown. The Spanish Flu obtained is name because Spain didn’t have such media blackouts and Spain was one of the hardest hit. The earliest case, however, was noted in Kansas, USA with others quickly following in France, Germany and the United Kingdom and soon, worldwide. But the Spanish Flu had already existed; for six days after the first case was reported, Camp Devens, Massachusetts, the US stated that there were 6,674 cases reported. Coming in three waves, the Flu was incredibly deadly, as with the Russian Typhus, further debilitating Europe on top of World War I. Numbers for the deaths range wildly with 25-50 million being a safe number with others topping up to 100 million deaths.

1. Black Death

Type: Bubonic Plague

Origin: Unknown: Potentially China and Central Asia

Deaths: 75-200 Million

The Second Bubonic Plague, the Black Death is the most deadly pandemic in human history. With an estimated 75-200 million dead, it created catastrophic change in warfare, politics and religion. With its origin beginning over 2000 years ago with strands of it occasionally breaking out, the Black Death had first reached Kaffa in Crimea in 1347. Europeans and some have heard stories about parts of Asia being hit hard by this new attack but in four years it had ravaged the European continent. It would make many resurgences for a few years at a time up to at least 1400 as it had been reintroduced to Europe over and over again due to trade and the fleas crawling on the backs of rodents. In spite of its name and reputation, some regions fared much better with virtually light casualties such as in Milan and Flanders while others were completely devastated like Tuscany, Aragon and Languedoc. Entire communities and families were wiped out with this deadly plague. In spite of its wide death estimates, it is undoubtedly the deadliest pandemic or epidemic in history. Even today the WHO reports that there remain between 1000-3000 cases of plague every year.