Smallpox, the most universally feared disease, killed nearly three hundred million people in the twentieth century alone. This is three times more than all the wars in the twentieth century combined. This virus does not infect animals, and it is limited to humans. Its course starts as an acute disease that produces distinct skin lesions, then afterwards leaves distinctive pock marks on the face of the survivor. Then after a ten to fourteen day incubation period in which the infected can still remain active, headache, fever and weakness suddenly occur. Smallpox can most easily be spread through the air, so people in a smaller, isolated community can avoid the virus, however once it's brought into the community the effects are horrendous.
The path of smallpox can be followed can be traced back along with the history of human migration. Assumptions are that it appeared in 10,000 B.C. in the great river basin.
Other early outbreaks of smallpox ranged from Syracuse to Athens, China the Korean Peninsula, and through Japan. Lack of a description of the rash from mummified bodies makes it tough to distinguish the rash of smallpox from other skin rashes such as the measles. Next we get into the role small pox played in the wars throughout time.
Through time smallpox has been used in war two ways, accidentally or purposely, I will go into examples of each. Smallpox was first recorded in battle in 570 when the Abyssinan army attacked the city of Mecca and the Arabs who were not yet Moslems. As written in the Koran, God sent birds that dropped stones on the attacking army causing sores and pustules. Their leader, Abraha, soon became contaminated and died. Following this the great Islamic expansion across North Africa spread small pox through Africa and into Europe.