More than 200 years ago, Edward Jenner performed an experiment that laid the foundation for the eradication of smallpox and transformed humankind's fight against disease. Smallpox afflicted humankind as no other disease had don; its persistence and diffusion were without parallel. The disease brought down at least three empires. Generations watched helplessly as their children succumbed to the disease or were disfigured or blinded by it. Attempts were made to contain smallpox by isolating its sufferers and, later, by using variolation with varying degrees of success. However, the definitive solution was not found until Jenner's work was done at the end of the 18th century. Milkmaids who had developed cowpox from contact with cow udders informed Jenner that they were protected from the human form of the disease; he listened to their folk wisdom and raised it to the status of scientific fact. Jenner did not discover vaccination, but he was the first to demonstrate that this technique offered a reliable defense against smallpox. It was also a reliable defense against other illnesses, such as poliomyelitis, measles, and neonatal tetanus, although this was not known in Jenner's lifetime.