Quetzalcoatl /ˌkɛtsɑːlˈkoʊɑːtəl/ (Classical Nahuatl: Quetzalcohuātl [ketsaɬˈko.aːtɬ]) is a Mesoamerican deity whose name comes from the Nahuatl language and means "feathered serpent". The worship of a feathered serpent is first documented in Teotihuacan in the first century BCE or first century CE. That period lies within the Late Preclassic to Early Classic period (400 BCE – 600 CE) of Mesoamerican chronology, and veneration of the figure appears to have spread throughout Mesoamerica by the Late Classic (600–900 AD).
In the Postclassic period (900–1519 AD), the worship of the feathered serpent deity was based in the primary Mexican religious center of Cholula. It is in this period that the deity is known to have been named "Quetzalcoatl" by his Nahua followers. In the Maya area he was approximately equivalent to Kukulcan and Gukumatz, names that also roughly translate as "feathered serpent" in different Mayan languages.
In the era following the 16th-century Spanish Conquest, a number of sources were written that conflate Quetzalcoatl with Ce Acatl Topiltzin, a ruler of the mythico-historic city of Tollan. It is a matter of much debate among historians to which degree, or whether at all, these narratives about this legendary Toltec ruler describe historical events. Furthermore, early Spanish sources written by clerics tend to identify the god-ruler Quetzalcoatl of these narratives with either Hernán Cortés or St. Thomas—an identification which is also a source of diversity of opinions about the nature of Quetzalcoatl.
Among the Aztecs, whose beliefs are the best-documented in the historical sources, Quetzalcoatl was related to gods of the wind, of Venus, of the dawn, of merchants and of arts, crafts and knowledge. He was also the patron god of the Aztec priesthood, of learning and knowledge. Quetzalcoatl was one of several important gods in the Aztec pantheon, along with the gods Tlaloc, Tezcatlipoca and Huitzilopochtli.