Aztec Empire


On a raised island in the shallow waters of Mexico’s Lake Texcoco in the 14th and 15th centuries, a triple alliance of warrior city-states known as the Aztecs built Tenochtitlan, one of the greatest cities in the Americas.

The Spanish conquistadors who would later lay siege and destroy the city—and rebuild what is now Mexico City—marveled at its striking beauty and sophistication (see images).


The Valley of Mexico is a basin with an average elevation of 7,000 feet surrounded by tall volcanic mountain ranges. At the time, Lake Texcoco sat at its center, an endorheic—or undrained—shallow lake fed by mountain snowmelt and rainfall.

The valley’s lands were nutrient-rich and arable, sustaining a strong agriculture and providing a surplus for a growing population. Lake-dwelling farmers built up patches of raised land in the lake known as chinampas, which continues today.


The name “Aztec” usually refers to a group of 13th-century migrants to the Valley of Mexico from the dried-out US Southwest (read 101).

This Nahuatl-speaking semi-nomadic group referred to their land of origin as Aztlan—or land of plenty—and later historians grouped them under the similar “Aztec” title (though it also can denote the Mexica tribe, as well as the city-states of the triple alliance).

At the time of the migration in the 1200s, hundreds of small, ethnic Indigenous city-states known as altepetl were already scattered around the valley and surrounding regions.

Though mostly independent and ruled by a king known as a tlatoani—or speaker—the altepetl were frequently subject to shifting imperial control and often required to pay tribute in return for protection.

The Alliance

The leaders of Mexica Tenochtitlan and nearby Tlacopan and Texcoco—city-states alienated from the dominant culture—joined forces to overcome Azcapotzalco, the most powerful city-state in the 1420s.

The three city-states used their combined military might to overpower nearby tribes and expand their territory, ushering in more than a century of Aztec control.

The Empire

As the Aztecs expanded, they would subdue local leaders but keep them in power, demanding regular tribute. At its height, the empire of over 5 million inhabitants included 80,000 square miles of land stretching from the Gulf of Mexico to the Pacific Ocean (what a day in Tenochtitlan was like).

Tenochtitlan quickly became the strong branch of the alliance. The city on a lake grew into a major trading hub as well as the empire’s religious center, particularly around the great Templo de Mayor pyramid, where the Aztecs sacrificed prisoners of war to their war god Huitzilopochtli and rain god Tlaloc (see visuals on gods).


Amid Spain’s colonization of the Caribbean islands in the early 1500s, Spanish conquistador Hernan Cortes set his eyes on Mexico (see timeline). Cortes would mimic the Aztecs by creating alliances with disgruntled vassals of the empire, ultimately splintering it and deposing Aztec leader Montezuma II and ending the Aztec empire’s hold on the region.

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Relevant articles, podcasts, videos, and more from around the internet — curated and summarized by our team

A stack of human skulls, likely belonging to victims of human sacrifice.
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The Aztecs controlled a vast territory through military might and intimidation. One very key—and to moderns, totally taboo—tactic of control was the ritual of human sacrifice, attested to by written accounts and archaeological discoveries at Tenochtitlan. While an effective scare tactic, the ritual was also based in fully-developed beliefs the world was sustained by blood. Dive into the fascinating history here.

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The Aztecs relied on the movements of the sun to determine their annual calendar primarily for agricultural use, but they calibrated it to a unique, long-mysterious ritual calendar involving symbols, ancient monuments, and more. Researchers have long puzzled over why their new year took place on February 23 of the Gregorian calendar, and they have utilized evidence from Aztec writings and ruins to show their highly advanced—and creative—process. Find out more here.

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The famous Aztec crystal skulls found in museum collections around the world—and immortalized by Indiana Jones—are, in fact, fabricated, and can all be traced back to one man: Eugène Boban, a French antiquities expert from the late 19th century. For over a century, the skulls fooled countless museum visitors until anthropologist Jane Walsh began investigating the objects more closely.

Indian Pueblo Cultural Center

Watch an Aztec fire serpent dance

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Get a taste of traditional Aztec dancing in this three-minute video of Danza Azteca performing a Xicauhuatl, or fire serpent, dance. Aztec and Mexica mythology believed fire serpents were responsible for carrying the sun across the sky each day, and incorporated symbols of the serpent in their religious rituals, including dancing alongside percussion. Watch more here.

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The most elite warriors of the Aztec civilization were known as the Eagles and the Jaguars, two sects distinguished by the particular gods they worshipped, according to this 18-minute video. Every male was trained from childhood to prepare them for war, from physical exercise to specific nutrition. See through some common misconceptions about the Aztecs and learn how their warriors trained with this fascinating video.

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For centuries, the story of Spain's takeover of the Aztec Empire suggested the empire's leader, Montezuma II, surrendered his lands and cities peacefully, and that a rogue band of Aztecs later launched a surprise attack against the conquistadors. But the evidence suggests no such peace took place amid the paradigm-shifting encounter between two men from totally different worlds. Learn more about the debate here.

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