Aztec

The Mexica, the people who built Tenochtitlan in 1325 CE on an island in Lake Texcoco, called themselves Mexica, not Aztec. In Nahuatl, the word Aztecatl (plural: Aztecah) meant someone from Aztlan, the mythical homeland where the Mexica believed their ancestors originated before a centuries-long migration southward. Aztlan's location was never fixed; it appears in Mexica migration accounts as a place of reeds and herons, possibly in the modern Mexican state of Nayarit. The Mexica used Aztecah in their migration narratives but dropped it as a living self-identifier once they founded their city.

Spanish conquistadors under Hernán Cortés arrived in Tenochtitlan in 1519 and called the inhabitants Mexicans or Indios, following naming conventions already established across New Spain. The Franciscan friar Bernardino de Sahagún compiled a twelve-volume encyclopedic account of Mexica culture, the Florentine Codex, completed around 1569, using Nahuatl terms throughout, including Aztecah in historical sections. But Aztec did not become the dominant European label for this civilization during the colonial period; Mexican and Mexica were the terms in common use in New Spain.

Alexander von Humboldt, the Prussian naturalist, changed that. His 1810 Vues des Cordillères et Monuments des Peuples Indigènes de l'Amérique introduced Aztèque to European scientific literature as the term for this pre-colonial civilization. Humboldt was systematizing indigenous American cultures for a European audience and chose the ancient migration name over the later city-centered name Mexica. William Prescott's enormously popular 1843 history, The Conquest of Mexico, then used Aztec throughout and fixed the term in English-speaking usage.

Today Aztec is the standard English word for the civilization, its language, and its people, even though contemporary Nahuatl scholars and many Mexican historians prefer Mexica for precision. The distinction matters because Aztec implies a fixed, unified empire while Mexica refers specifically to the Nahua-speaking people centered at Tenochtitlan. Nahuatl itself is still spoken by approximately 1.7 million people in Mexico. The word Aztec carries the weight of a name given by outsiders and then internalized so thoroughly it became a civilization's primary label across most of the world's languages.