 During the early years following the Conquest, Spaniards quickly realized that pre-Conquest Mexicans possessed a complex and sophisticated system of beliefs about human beings and the universe. In his Historia general de las cosas de la Nueva España (1585 [1950–1982]), the Franciscan missionary Bernardino de Sahagún (1499–1590) reproduced the ancient Mexican worldview through documents and testimonials. Centuries later, with the discovery of new documents and a deeper knowledge of indigenous languages, we have improved our understanding of how the original inhabitants of Mesoamerica viewed the world.