HuitzilopochtliThis painting of the hummingbird god of war carrying a shield in one hand and a serpent-headed knife in the other was made by Aztec priests in a book written on bark paper about the time of the Spanish conquest. He is shown descending from a step-pyramid, perhaps a reference to the great pyramid in the center of Tenochtitlan, where he was worshipped. (© Foundation for the Advancement of Mesoamerican Studies, Inc., www.famsi.org)