1. The Black Death (1346 - 1665)

The Black Plague killed almost 60% of the population in Europe at the time as it gives other implications to the world in terms of its economy and social system.

Starting in 1346, the effects of the plague kept being felt for several decades and came to an end during the London Plague in 1665.

The London plague was believed to be the final stage of this plague killing more than 100,000 people as we witnessed London losing a quarter of its original population. Overall, 75 - 200 million died from this devastating attack ever faced by mankind.

2. Third Plague Pandemic

It was believed to be active until the 1960s, this long occurring plague started off in the region of Yunnan, China in 1855. The Yunnan Plague was rampant due to the number of rodents patrolling in the area as well as the migration of the Hans people into Yunnan due to the high demands of mining activities.

The overly dense populated areas caused the plague to quickly spread from one person to another following Yunnan's economy which was thriving as there were as many as 7 million people living there.

 As this huge population of migrants went back to their hometown, this caused the plague to spread to other parts of the country like Guanxi and Guangdong, Hainan Island, Canton and also Hong Kong.

In Canton alone, 60,000 people died of the plague. Economic and trading activities caused the disease to also spread to India in 1896 which was believed to be the relation of businesses in Hong Kong. In just 30 years, around 12.5 million Indians have died.

Reports regarding similar diseases have been sighted in other countries like Japan, the Soviet Union, Burma, Tunisia, Brazil, and many more. It was only in 1897, a vaccine for the disease has been successfully developed which took 60 years before the plague was announced in control.

3. Justinian's Plague (541 - 542)

The Plague of Justinian shook the people of Constantinople(now Istanbul) in 541 during the rule of the Byzantine Empire. Aside from Constantinople, this plague was also swarming across the ports of the Mediterranean Sea and a big part of the Sasan empire of Persia.

It was estimated that around 25 to 50 million lives were lost due to this plague which is equivalent to 13 -26% of the world's population at the time. The plague was named after King Justinian I who rule the eastern Roman empire at the start of the plague with the king himself also affected.

However, the king was quite lucky to survive the infection. This huge plague was the first ever to be recorded in history with regard to an organism attack called yersinia pestis. This bacteria is responsible for many deaths around the world.

According to studies, this bacteria was found in Central Asia as it spreads through the vector of insects.

 4. Cocoliztli Epidemics (1545 - 1576)

In the beginning, the people living in the area known as Mexico were estimated to be 25 million people. The Aztecs living in the area were well known for their historic glory back in the day.

However, in the 16th century, only 1.2 million people remained in the area. Records have shown that in 2 periods of time which were in 1545 and 1576, there was a plague attack taking more than 17 million lives resulting in the fall of the Aztec civilization.

Notes of a medical researcher named Fransisco Hernandez that witnessed the attack said the victim experience fevers, chest pain, and convulsion while blood flows out of their ear and nose.

The fever was believed to have come from a rodent infestation during the monsoon season. The disease is known by the locals as cocoliztli and it was somewhat resembling waterpox disease.

5. Italian Plague (1629 - 1631)

Starting in 1629 until 1631, the Italians were shocked by a deadly plague hitting Milan. It was all due to the entry of the Germans and French army into the area as they fled to Milan to avoid war.

Occurring in several waves, the failure of the Milan authority in controlling the situation caused the plague to spread easily. In this bubonic-type attack, 60 thousand people died which was almost half of the population of Milan which was at 130,000.

The disease then spread to Florence city adding to the death counter of 9,000 people. It was estimated that the Italian Plague killed 140,000 people with some cities like Verona losing 60% of its residents.

 6. Athens Plague (429 BC)

The Athens Plague attacked the people of Athens during their civil war against the Peloponnesian league led by the Spartans. It was believed to have been caused by the food supply coming from their port in Piraeus as the plague-infected them 3 times from 429 BC until 426 BC.

It was unclear what attacked them exactly but many beliefs said that it was due to the bubonic plague of bacterial infection causing swelling on their skins. Some also said that the people of Athens were dealing with poxes, typhoid or rubella.

As much as 25% of the whole population of Athens died of the disease. The discovery of 1,000 individual graves and a big fortress in 1994 placed almost 250 bodies underground. This also showed that the people of Athens were forced to bury the dead in a disorganized manner.