Several major civilizations rose and fell across Mexico and Central America long before the Aztecs came to power. The Aztec Empire, formally established as the Triple Alliance in 1428, was actually a latecomer to Mesoamerican history. By the time the Mexica people (the Aztecs’ core group) arrived in the Valley of Mexico around 1248, the region had already seen nearly 3,000 years of complex urban societies, monumental architecture, and sophisticated calendars.
The Olmec: Mesoamerica’s Earliest Complex Society
The Olmec are widely regarded as the foundational civilization of Mesoamerica. Flourishing during the Early and Middle Formative periods (roughly 1500 to 400 BCE) along the Gulf Coast of what is now southern Mexico, they established some of the region’s first major ceremonial centers. Their most famous legacy is their colossal stone heads, but their influence ran far deeper. A 2022 study published in Science Advances found that architectural alignments at Olmec sites dating to 1100 to 750 BCE represent the earliest known evidence of the 260-day ritual calendar, the same sacred cycle that the Aztecs and nearly every other Mesoamerican civilization would later use. Before that study, the oldest confirmed calendar records dated to roughly 300 to 200 BCE from Maya sites in Guatemala.
The Olmec established patterns of urban planning, religious symbolism, and long-distance trade that rippled through the region for millennia. They weren’t an “empire” in the way we’d recognize one, but their cultural fingerprints appear in virtually every civilization that followed.
Teotihuacan: The First Great Metropolis
By the early centuries of the Common Era, the city of Teotihuacan in central Mexico had grown into one of the largest cities in the ancient world. Located just 30 miles northeast of where Mexico City stands today, it dominated the region during the Classic Period. Its massive Pyramid of the Sun and Pyramid of the Moon anchored a carefully planned urban grid, and the city served as a hub of trade, religion, and political power across Mesoamerica.
Teotihuacan collapsed around 600 CE in a dramatic episode sometimes called the “Big Fire.” More than a hundred structures were burned, sculptures were smashed and scattered, and the state’s governing apparatus never recovered. The causes remain debated, but the city’s fall created a power vacuum that reshaped the political landscape of central Mexico for centuries. When the Mexica arrived in the Valley of Mexico over 600 years later, Teotihuacan’s ruins were already ancient and overgrown, yet still awe-inspiring enough that the Aztecs incorporated the site into their own origin myths.
The Zapotec at Monte Albán
While Teotihuacan dominated central Mexico, the Zapotec civilization built its own impressive state in the Oaxaca Valley to the south. Their capital, Monte Albán, was established around 500 BCE on a strategically chosen hilltop offering commanding views of the surrounding valleys. The city grew steadily for over a thousand years. During its earliest phase, from 500 to 300 BCE, the population already exceeded 5,000 people, representing at least half the valley’s entire population.
Monte Albán reached its peak between 200 and 700 CE, when the population swelled to around 115,000 and the city sprawled across neighboring ridges and valleys. The Zapotec developed one of Mesoamerica’s earliest writing systems and built elaborate tombs decorated with vivid murals. After 700 CE, centralized control broke down and administrative power shifted to smaller, autonomous areas. The capital’s population plummeted from about 16,500 to an estimated 4,000. Later, the Mixtec people moved into parts of the Oaxaca region, often reusing Zapotec sites, including Monte Albán’s tombs, for their own burials.
The Classic Maya
To the east, Classic Period Maya society (roughly 250 to 850 CE) built an extensive network of cities across parts of modern Mexico, Guatemala, Belize, and Honduras. This wasn’t a single empire but a collection of competing city-states, each ruled by its own dynasty. The largest cities held populations of 50,000 to 120,000, and recent lidar scanning of a 95,000-square-kilometer area of the central Maya lowlands estimates the total Late Classic population at 9.5 to 16 million people.
The Maya developed the most sophisticated writing system in the Americas, built towering limestone pyramids, and made precise astronomical calculations. Their political collapse unfolded during the 9th century, when major cities in the southern lowlands of Guatemala and Belize were abandoned within a span of 50 to 100 years, generally between 800 and 900 CE. Severe and frequent droughts played a role, but the collapse was uneven. Cities in northern Yucatán, particularly Chichen Itza, actually rose to prominence during this period, commanding seaborne trade routes and building alliances across the region. Chichen Itza itself fell from power by the 11th century, and the city of Mayapan filled the void around the mid-12th century. Maya civilization never truly vanished. Postclassic Maya states continued thriving along the coasts of the Caribbean and Gulf of Mexico well into the period of Aztec dominance.
The Toltec: Direct Predecessors to the Aztecs
Of all the civilizations that preceded the Aztecs, the Toltec held the most direct influence over them. Based at their capital of Tula (in modern Hidalgo state), the Toltec peaked between 950 and 1150 CE, placing them squarely in the gap between Teotihuacan’s fall and the Aztec rise. Tula served as a major civic and religious center, and its architectural layout became a prototype for the central precinct of the Aztec capital Tenochtitlán.
The Aztecs actively sought to connect themselves to Toltec heritage. They incorporated Toltec architectural styles, mythology, and religious practices into their own culture. Archaeologists have found artifacts that Aztec peoples systematically looted from Tula’s ruins, centuries after the city’s fall, during excavations of Tenochtitlán. The Toltec legacy also carried a powerful religious dimension. The legend of the feathered serpent god Quetzalcóatl, which the Aztecs inherited from Toltec tradition, held that the deity would return from the east. That prophecy, tied to a year coinciding with 1519 in the European calendar, may have shaped the Aztec response to the arrival of Hernán Cortés.
How the Aztecs Fit Into This Timeline
The Mexica were part of a broader wave of Nahuatl-speaking migrations into central Mexico. They weren’t the first to arrive. Earlier Nahuatl-speaking groups, including the Xochimilca, Chalca, Tepaneca, and Acolhua, settled in the Basin of Mexico around 1195 on average. A second wave, including groups that settled in Tlaxcala and surrounding highland valleys, arrived around 1220. The Mexica came last, reaching the Basin of Mexico around 1248.
As latecomers, the Mexica found the best land and resources already claimed by established groups. They spent decades as vassals and mercenaries before founding Tenochtitlán on a marshy island in Lake Texcoco around 1325. It took another century of strategic warfare and alliance-building before they formed the Triple Alliance with the rulers of Tetzcoco and Tlacopan in 1428, formally launching the Aztec Empire. By that point, Mesoamerica had already produced complex urban civilizations for nearly 3,000 years. The Aztecs built on that accumulated knowledge, borrowing calendars, architectural forms, religious concepts, and agricultural techniques from the many societies that came before them.