Teotihuacan Founded

Teotihuacan, in the Basin of Mexico about 40 kilometers northeast of modern Mexico City, grew from a cluster of settlements in the last centuries BCE into one of the largest and most influential cities of the ancient world. The date of about 100 BCE marks the approximate beginning of its rise rather than a single founding moment, and archaeologists still debate exactly how and when the city took shape. What is clear is that it became the first great urban center of central Mexico, with a reach that extended across Mesoamerica.

The background lies in the changing fortunes of the Basin of Mexico. Earlier farming villages had grown up around the lakes and fertile lands, and the nearby center of Cuicuilco in the south was a major settlement. A volcanic eruption of Xitle is often linked to Cuicuilco's decline, and some scholars suggest that displaced people moved north to Teotihuacan, though this is debated. The Teotihuacan valley offered springs, good farmland, and access to obsidian sources, a valuable resource for tools and weapons that fueled trade.

Over the following two or three centuries the settlement expanded dramatically. By roughly the first to third centuries CE, the city was laid out on a remarkably regular grid, centered on a broad avenue now called the Avenue of the Dead. Along it rose the Pyramid of the Sun, one of the largest structures in the pre-Columbian Americas, along with the Pyramid of the Moon and the Ciudadela complex, which includes the Temple of the Feathered Serpent. Much of the population lived in walled apartment compounds, many decorated with colorful murals. Estimates of the city's peak population commonly range from around 100,000 to 200,000 people, though these figures are uncertain.

Teotihuacan's economy relied on agriculture, craft production, and long-distance trade, especially in green obsidian from the Pachuca area. Its distinctive architectural style and pottery appear far from the valley, including in Maya cities such as Tikal, where inscriptions and artifacts suggest strong, and at times forceful, contact in the fourth century CE. Whether Teotihuacan ruled these regions directly or influenced them through diplomacy, trade, and alliance is still argued.

The city declined around the sixth to seventh centuries CE. Evidence of fires in the ceremonial center suggests violence or upheaval, though internal unrest, economic strain, and environmental pressures may also have played roles. Even in ruin it remained sacred: the later Aztecs gave the site its name, meaning roughly "place where the gods were created," and revered it as a place of origins. Today it is a UNESCO World Heritage Site, and its language, rulers, and founders remain largely mysterious, since the city left little decipherable writing.