The Aztec Migration: From Mythic Aztlán to the Founding of Tenochtitlan

Origins of the Mexica

The people known as the Aztecs (self-designation: Mexica) traced their origins to Aztlán ("Place of Whiteness" or "Place of Herons"), a semi-legendary homeland believed to lie in northern Mexico or the southwestern U.S. (possibly Nayarit, Zacatecas, or even southern Arizona/California).

The Migration (c. 1100–1325 CE)

• Guided by their patron god Huitzilopochtli, the Mexica wandered for ~200 years.
• Served as mercenaries for city-states in the Valley of Mexico (Culhuacan, Azcapotzalco).
• Expelled from Culhuacan after a scandal involving a sacrificed princess.
• Settled on marshy islands in Lake Texcoco after seeing the prophesied sign: an eagle on a cactus devouring a serpent.

Founding of Tenochtitlan (1325)

On the island(s), they built Tenochtitlan—a city of canals, causeways, chinampas (floating gardens), and temples. Through the Triple Alliance (1428) with Texcoco and Tlacopan, they became the dominant power in Mesoamerica.

Historicity of Aztlán

Most scholars view Aztlán as a mythologized ancestral homeland, not a single locatable place. The migration narrative legitimized Mexica rule by linking them to the prestigious Toltec tradition and the broader Chichimeca northern ancestry.