The history of the evangelization of indigenous people of Mexico and Central America to Catholicism. Describes how the Aztec Empire fell to the conquistadores from Spain, and the beautiful new land discovered. His writings are key for understanding history and ethnography of the Nahuas in the post-conquest. He tells of what he considered the ten plagues afflicting New Spain, like the biblical Ten Plagues: smallpox was the first, the second, those who died in the conquest; the third, famine following the fall of Tenochtitlan; the fourth, labor bosses and tribute collectors; the fifth, tax and tribute obligations; the sixth, forced labor in gold mines; seventh, building Mexico City; the eighth, enslavement; the ninth, the labor far from homes; and the tenth plague, the factionalism of Spanish conquistadores.