Most American schoolbooks claim that the Aztec ruler Moctezuma II confused the Spanish conquistador Hernan Cortes for the Aztec god Quetzalcoatl, a fabulous, fair-skinned priest king of ancient times who had promised to return, which is why Moctezuma voluntarily surrendered his mighty empire. In the past, the tale of Quetzalcoatl has inspired many people to speculate about pre-Columbian invaders from the Old World. It has also been abused as another presumed proof of white supremacy. Indigenous traditions, however, saw a Mexican Messiah who played an important part in constructing the Mexican national identity. This book demonstrates that the story of the returning god is a product of "fake news" uttered by Cortes. It does so by analysing the most important sources of the Quetzalcoatl-tale. A systematic context-enlargement that also includes ethnographic information and contemporary history reveals why and how Cortes constructed this story, and why and how the Aztec elite adopted it. This method proves to be an epistemological tool which allows researchers to identify pre-Hispanic information in ethnohistorical texts of colonial times. As a result, the true Quetzalcoatl behind the legend comes to light.