Cortes and The Aztecs
In the early 16th century, Spanish conquistador Hernan Cortes de Monroy Pizarro led an expedition to what is now Mexico, which resulted in the total destruction of the Aztec Empire within just two years (February 1519-August 1521). Notwithstanding the Europeans' superior weaponry, it is believed that the arrival of smallpox in the Americas in 1520 weakened the resistance the Aztecs people were able to mount.
Read more about this topic: Ecological Imperialism