Where did this disease emerge from? No one knows this. But it is estimated that around 10,000 BC, when humans turned to agriculture for the first time, the first farming settlements were seen in Africa, and humans began the domestication of cattle and poultry, then humans came into contact with these animals for prolonged periods. These orthopox viruses are normally found in these mammals. So it is assumed that it must have come from somewhere there. Some scientists believe that it could have come from rodents as well.
But the first evidence of this disease was found in 1156 BC. When an ancient Egyptian Mummy, was embalmed and laid to rest, that had the same scarring on the face that happened due to smallpox. It has been mentioned in ancient texts in India and China. In the Sanskrit text Susruta Samhita, written around 6th century BC, this is mentioned.
Since then we have found no cure for this deadly disease. Modern medicine has no cure for Smallpox till today. But one this is for sure, for a long time, people understood the concept of immunity, People noticed that the people who survived this disease, weren’t infected by it again. So several doctors deduced that one way to be safe from this disease would be to infect the person with a small dose of the virus before it could infect them. It might make them sick, but it wouldn’t kill them, hopefully, and later they wouldn’t have to go through with it. This process is called Inoculation.