The Mexica or Aztec Empire

The Mexica, or Aztecs, were one of the Nahuatl-speaking peoples who came from the north starting in the 13th century to settle in the central valley of Mexico, also known as the Valley of Anáhuac.

According to their origin myth, they left their homeland, known as Aztlán, and, guided by their patron god Huitzilopochtli, to found a city at the place where they would find an eagle perched on a cactus devouring a serpent.

After wandering through the region, they saw this sign on an islet in Lake Texcoco—which has since disappeared beneath modern-day Mexico City – and founded Tenochtitlan there in 1325. This site lay within the territory of the city of Azcapotzalco, to which they had to pay tribute.

In 1386, the Mexica formed an alliance with the lords of Culhuacán by choosing one of their sons as their tlatoani, that is, their king, and thereby established a new dynasty.
The Mexica quickly distinguished themselves militarily and expanded their territory, even though they themselves remained vassals.

In 1427, a succession crisis in Tenochtitlan brought Itzcóatl to power, who founded the Triple Alliance with the cities of Texcoco and Tlacopan. This military confederation was victorious over the city of Azcapotzalco and extended its domination over the entire valley and its surrounding areas.

Within a few decades, Tenochtitlan broke the balance of power within the Triple Alliance in its own favor and created the Mexica Empire.

In 1440, Moctezuma I initiated a nearly century-long period of conquest. He and his successors imposed economic, military, and religious domination over the central valley of Mexico, and then over a much larger area extending from the shores of the Gulf of Mexico to the Pacific Ocean and the Soconusco region. All these territories became tributaries of the Empire; however, the Tarascan Empire, Tlaxcala, and Teotitlán maintained their independence, though at the cost of constant conflict with the Mexica.

Meanwhile, in 1470, the neighboring city of Tlatelolco was annexed, creating the twin city of Tenochtitlan–Tlatelolco. In this new configuration, Tenochtitlan—organized around the Templo Mayor and the surrounding palatial zone—consolidated its ceremonial and political role, while Tlatelolco became the commercial center of the Mexica world.

The influx of tribute from the new provinces led to a rapid expansion of the capital. The construction of chinampas—structures made of logs and branches filled with earth and sediment—made it possible to reclaim land from the lake, develop agriculture and build structures. This system provided the foundations for monumental architecture with vast plazas, pyramidal structures, and the emergence of residential districts. Access to the city was limited to three major causeways linking it to the lakeshore.

The last tlatoani, Moctezuma II, had to confront the arrival of Europeans led by Hernán Cortés. Cortés allied himself with several Totonac cities on the coast and with other peoples, including the Tlaxcalteca, in order to undertake the conquest of Tenochtitlan.
The city fell after a long siege in the summer of 1521, marking the end of the Mexica Empire.