Aztec Empire history: Tenochtitlan, 3-city power, 1521

From an island city to an alliance

Aztec Empire history begins with a city founded on water and a pact that changed the Valley of Mexico. In 1325, the Mexica founded Tenochtitlan on an island in Lake Texcoco, and in 1372 Acamapichtli was enthroned as its first tlatoani.

The Aztec Empire was not a single city ruling alone. It was an alliance of three Nahua city-states: Mexico-Tenochtitlan, Tetzcoco, and Tlacopan. After the war against Azcapotzalco, the Triple Alliance was formally created in 1430.

How Tenochtitlan took the lead

Tenochtitlan gradually became the dominant power in the Triple Alliance during the next one hundred years. Before the Spanish arrived in 1519, it had become the leading power in the alliance.

At its peak, Tenochtitlan was the largest city in the pre-Columbian Americas. That rise was not only about size. Moctezuma I created a new title, quauhpilli, for commoners who distinguished themselves in military or civil service.

The empire also used war in a very specific way. Flower Wars were pre-arranged for the purpose of collecting prisoners for sacrifice to the gods. Those battles fit into a political and religious world shaped by tribute, rank, and ritual.

War, invasion, and military strength

Aztec power showed itself far beyond the Valley of Mexico. In 1479, Axayacatl launched a major invasion of the Purépecha Empire with 32,000 Aztec soldiers.

The campaign ended in disaster. The Purépecha defeated Axayacatl's army, killing or capturing over 90% of it. Even after that defeat, Tenochtitlan continued to hold a central place in the alliance.

Cortés reaches the empire

In 1519, Hernán Cortés landed in Yucatán with approximately 630 men. La Malinche became a key figure in his interactions with Nahua rulers, helping shape the negotiations that followed.

Cortés arrived in Tenochtitlan on 8 November 1519. By then, the city had already become the dominant power in the Triple Alliance, and it stood at the center of a political world that had lasted for generations.

The alliance ruled the Valley of Mexico from 1428 until the Spanish and their native allies defeated them in 1521. That long arc runs from the island founding of Tenochtitlan to the fall of the empire nearly two centuries later.

Who ruled the Aztec Empire?

The Aztec Empire was ruled through the Triple Alliance of Mexico-Tenochtitlan, Tetzcoco, and Tlacopan. Tenochtitlan became the dominant power, but the alliance itself was the structure that held the empire together.

Its rulers, military campaigns, and tribute system shaped the Valley of Mexico for decades. From the enthronement of Acamapichtli in 1372 to the defeat in 1521, the story of the empire is tightly tied to the rise of Tenochtitlan.

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