Coatepec, or Serpent Mountain, from the Nahuatl words coatl, serpent, and tepetl, mountain, was one of the most sacred places of Aztec mythology and religion. Coatepec was the birthplace of the god Huitzilopochtli, and the place where the newly born god, fully armed, managed to kill his sister Coyolxauhqui when she attempted to kill their mother Coatlicue, with the help of her brothers, the Four Hundred Southerners.
During the migration from their mythical homeland Aztlan, the Mexica/Aztecs reached Coatepec on their journey toward Central Mexico. According to different codices and to historian Bernardino de Sahagun, the Aztecs stayed at Coatepec for almost 30 years and built a temple on top of the hill in honor of their patron deity Huitzilopochtli.
In his Primeros Memoriales, Bernardino de Sahagun records that a group of the migrating Mexica wanted to split from the rest of the tribes and settle at Coatepec. This fact really angered Huitzilopochtli who descended from his temple and forced the Mexica to resume their journey.
The Templo Mayor of Tenochitlan: A Replica of Coatepec
Once they reached the Valley of Mexico and founded their capital Tenochtitlan, the Mexica wanted to create a replica of the sacred mountain at the heart of their city. As many Aztec scholars have demonstrated, the Templo Mayor (Great Temple) of Tenochtitlan, in fact, represents a replica of Coatepec. Archaeological evidence of this correspondence was found in 1978, when a stone sculpture of the dismembered Coyolxauhqui was discovered at the base of the Huitzilopochtli side of the temple during some electric works in the center of Mexico City.
This sculpture perfectly corresponds to the Aztec myth in which Huitzilopochtli, after killing her sister, threw her severed remains down the mountain of Coatepec.
Coatepec and Mesoamerican Mythology
Recent studies have demonstrated how the idea of a sacred Snake Mountain was already in place in Mesoamerican mythology well before the arrival if the Aztecs in Central Mexico. Main temples such as the one at the Olmec site of La Venta, or at early Maya sites like Cerros and Uaxactun, as well as the Temple of the Feathered Serpent at Teotihuacan have been proposed as antecedents to the Aztec replica of Coatepec
Miller, Mary and Karl Taube, 1993, An Illustrated Dictionary of the Gods and Symbols of Ancient Mexico and the Maya, Thames and Hudson.
Schele, Linda and Julia Guernsey Kappelman, 2001, What the Heck’s Coatepec. The Formative Root of an Enduring Mythology, in Rex Koontz, Kathryn Reese-Taylor and Annabeth Headrick (Eds.), Landscape and Power in Ancient Mesoamerica, Westview Press, Boulder Colorado, pp 29-53