Pandemics along history

Plague of Justinian(541-542 A.D.)

541 BCE

Originated in the Byzantine Empire age. Caused by the bacteria Yersinia pestis, it killed from 25-50 million people, it was also one of the main factors that destabilized the Roman Empire, directing it to its imminent fall.

Black Death

1347

In 1347, ships returned to Sicily, Italy with a foreign(but lethal) disease that caused the surgeon of dark swellings in the skin. Venetian people banned travelers to enter the country if they hadn't passed 40 days of isolation, known as "Quaranta Giorni"(Nowadays quarantine).
Even with those efforts, this plague killed around 200 million people in the world(1/3 of global population in those days)

Spanish Flu

1918

It infected around 500 million people around the globe.
The main infected people were young adults aged 20-24 years, on average. By 1920. 50-100 million people lost the fight against these diseases.

Covid-19 Pandemic

2020

The most recent pandemic around the world, with 628 million people infected, and aproximately 6.58 million deaths.
It's estimated that began in China, specificly in a market(or in a laboratory).
This deadly virus is transmited through the air with sneezes or coughs, fortunately few vaccines have been invented, and there are safety measures to avoid getting infected, like the usage of masks or the safety distance(approximately from 1-2 meters)