The infected slave, Francisco de Eguía, was brought over from Cuba to the mainland by a Spanish ship in March of 1520. The indigenous population had no immunity to smallpox and it spread like wildfire. By October of the same year smallpox had entered into the Aztec capital Tenochtitlan and killed a third of the citiy’s population, including the emperor. By December, 9 months after the deadly had been introduced, the population of native Mexicans had fallen from 22 million to 14 million.
A Spanish monk who witnessed the epidemic said: “It became such a great pestilence among them throughout the land that in most provinces more than half the population died; in others the proportion was less. They died in heaps, like bedbugs.”
