These are the seven deadliest diseases to have plagued humankind in recorded history. Most of them have taken millions of lives. Some of the worst are still killing people today. Thankfully, the worst one of all has been eradicated.

#7 - Typhus (430 BC? - today)

The name Typhus comes from the Greek word typhos, meaning smoky or lazy, describing the state of mind of those affected. 3 million people were killed between 1818 and 1822 alone, including most of Napoleon’s soldiers. Typhus is spread by louse-borne bacteria that reside on mice and rats. The disease flourishes under poor hygienic conditions, such as prisons, refugee camps, amongst the homeless, and in military camps out in the field (until recently).

 A possible first outbreak of the disease was reported in a convent in Italy in 1083. However, the first epidemic was in Athens during the Peloponnesian War. It was known as the Plague of Athens. Since then a number of other epidemics have occurred all over the world. President Franklin Pierce’s son died from it in 1843. A vaccine was developed during WWII. Now epidemics only occur in Eastern Europe, Middle East and parts of Africa.

#6 - Cholera (1817 - today)

Cholera was the first truly global disease. Ten years after it was first reported it was the most feared disease in the world. Through eight pandemics cholera has killed hundreds of thousands worldwide.

 Attendees of a festival in Calcutta first contracted Cholera in 1817 and carried it back to their homes and cities. It travelled quickly by ship to all parts of the globe, carried in contaminated water and in the excrement of victims.

#5 - AIDS (1981 - today)

Acquired Immune Deficiency Syndrome (AIDS) may be the youngest disease on this list, but it has made a deadly mark in its short history. In thirty years AIDS has killed 25 million people worldwide, 3.1 million in 2005 alone, and it is estimated that 40.3 million people are now living with the HIV virus. Cases of the disease continue to rise in most parts of the world.

#4 - Malaria (1600 - today)

Potentially Malaria-Carrying MosquitoMalaria continues to be one of the most deadly of all diseases in history, but, unfortunately in it not only an historical disease. On average, two million people die each year from malaria, one person every 30 seconds, and 400-900 million are affected by it annually. Most of the deaths are in children under age 5, pregnant women and the elderly. Malaria deaths are on the rise, and could double in 20 years. Malaria is spread by mosquitoes. Symptoms include anemia, fever, chills, nausea, flue-like symptoms, and in severe cases, coma and death.

#3 - Black Death (1340 - 1771)

The Black Death, also known as the Black Plague, was actually three simultaneous diseases. Bubonic plague was the most potent, but many also died from septicaemic plague and pneumonic plague. This pandemic began in South-western or Central Asia and spread to Europe in the late 1340s. It is believed that between a third and two thirds of all Europeans were killed by it, and approximately 75 million people in all have perished from the Black Death.

#2 - Spanish Flu (1918 - 1919)

Thankfully the Spanish Flu only lasted two years! Between 50-100 million people lost their lives in just that short span of time. The symptoms began as a severe flu, but then turned much worse in many victims. Once the flu passed beyond the normal range of symptoms there was little hope of survival. Even today there is no cure for the flu, and antibiotics were not available at that time. The first cases were found in a military camp in the United States, but it was soon found that the disease was all over the world, with approximately one billion infected by it.

#1 - Smallpox (430 BC? - 1979)

The worst and most deadly of all diseases in history is smallpox. This destructive plague killed 300 million people worldwide in the 20th century alone! It is estimated that 60 million were killed in Europe in the 18th century. The World Health Organization estimated that 15 million contracted, and 2 million died from smallpox in 1967. Two virus variants, Variola major and Variola minor, were responsible for the disease. V major killed about 30-35% of its victims while V. minor killed ~1%.

Smallpox VaccineSuccessful vaccination campaigns throughout the 19th and 20th centuries led to a complete eradiciation in 1979. Although small pox is the most deadly disease in history, it remains the only human infectious disease to have been completely eradicated.