Teotihuacan Timeline

By the 1300s, Teotihuacan had fallen under the sway of Huexotla, an Acolhua polity in the Valley of Mexico.

Image source: Huejotla

The name Teōtīhuacān was given by the Nahuatl-speaking Aztecs centuries after the fall of the city around 550 CE. The city predates the Aztec Empire by many centuries.

In 1409 Teotihuacan was assigned its own tlatoani, Huetzin, a son of the tlatoani of Huexotla.

Huetzin's reign was cut short when Tezozomoc, tlatoani of Azcapotzalco, invaded Huexotla and the neighboring Acolhua lands in 1418.

Image source: Tezozomoc (Azcapotzalco)

Less than a decade later, in 1427, the Aztec Empire formed, and Teotihuacan was vassalized once more by the Acolhua.

Image source: Aztec Empire

The 1580 relacion geografica of Teotihuacan affirmed that Nahuatl was the most common language, but minorities spoke Otomi and 'Popoloca' (possibly identified with the modern Popoloca languages).

In the late 17th century Carlos de Sigüenza y Góngora (1645–1700) made some excavations around the Pyramid of the Sun.

Image source: Carlos de Sigüenza y Góngora

Minor archeological excavations were conducted at Teotihuacan during the 19th century.

The site of Teotihuacan was the first to be expropriated for the national patrimony under the Law of Monuments (1897), giving jurisdiction for the Mexican state to take control.

In 1905 Mexican archeologist and government official Leopoldo Batres led a major project of excavation and restoration under the regime of Porfirio Díaz.

A feeder train line was built to the site in 1908, which allowed the efficient hauling of material from the excavations and later brought tourists to the site.

In 1910, the International Congress of Americanists met in Mexico, coinciding with the centennial celebrations, and distinguished delegates such as president Eduard Seler and vice president Franz Boas were taken to the newly finished excavations.

The Pyramid of the Sun was restored to celebrate the centennial of the Mexican War of Independence in 1910.

Image source: Pyramid of the Sun

Between April 26 and July 29, 1932, Swedish anthropologist/archaeologist Sigvald Linné, his wife, and a small crew excavated in the Xolalpan area, part of the municipality of San Juan Teotihuacán.

Image source: Teotihuacan

The first site-wide project of restoration and excavation was carried out by INAH from 1960 to 1965, supervised by Jorge Acosta.

During the installation of a 'sound and light' show in 1971, workers discovered the entrance to a tunnel and cave system underneath the Pyramid of the Sun.

In 1980–82, another major program of excavation and restoration was carried out at the Pyramid of the Feathered Serpent and the Avenue of the Dead complex.

Image source: Temple of the Feathered Serpent, Teotihuacan

In late 2003 a tunnel beneath the Temple of the Feathered Serpent was accidentally discovered by Sergio Gómez Chávez and Julie Gazzola, archeologists of the National Institute of Anthropology and History (INAH).

Before the start of excavations, beginning in early 2004, Victor Manuel Velasco Herrera of UNAM Institute of Geophysics used ground-penetrating radar with a team of about 20 people to determine the approximate length of the tunnel and the presence of internal chambers.

Image source: Ground-penetrating radar

By 2005, the digital map of the tunnel beneath the Temple of the Feathered Serpent was complete.

In 2009, the government granted Gómez permission to dig into the tunnel beneath the Temple of the Feathered Serpent.

By the end of 2009 archeologists of the INAH located the entrance to the tunnel that leads to galleries under the pyramid, where remains of rulers of the ancient city might have been deposited.

The hole that had appeared during the 2003 storms was not the actual entrance; a vertical shaft of almost 5 meters by side is the access to the tunnel.

In August 2010 Gómez Chávez announced that INAH's investigation of the tunnel – closed nearly 1,800 years ago by Teotihuacan dwellers – would proceed, with entry planned for September–October 2010.

By 2015 nearly 75,000 fragments of artifacts had been discovered, studied, cataloged, analyzed and, when possible, restored.

A recent discovery of an 1800-year-old bouquet of flowers was made in 2021 at the site.

The site covers a total surface area of 83 square kilometers (32 sq mi) and was designated a UNESCO World Heritage Site in 1987.

In 2001, Terrence Kaufman presented linguistic evidence suggesting that an important ethnic group in Teotihuacan was of Totonacan or Mixe–Zoquean linguistic affiliation.

Image source: Terrence Kaufman

In 2004, the governor of Mexico state, Arturo Montiel, gave permission for Wal-Mart to build a large store in the third archeological zone of the park.

The significance of these new discoveries is publicly explored in a major exhibition at the De Young Museum in San Francisco, which opened in late September 2017.

Image source: De Young Museum

As of January 23, 2018, the name Teotihuacan has come under scrutiny by experts, who now feel that the site's name may have been changed by Spanish colonizers in the 16th century.

In May 2021, the Secretariat of Culture announced that a construction crew had been bulldozing the northern outskirts of the city ruins to develop land for an amusement park, despite three months' worth of orders from the government to stop work.

On May 31, 2021, 250 National Guard troops and 60 agents of the Attorney General's Office were sent to the Teotihuacán site to seize parcels of land intended for illegal construction and to forcibly stop further destruction of historical sites.

Teotihuacan was the second most-visited archeological site in Mexico in 2024, receiving 1,313,321 visitors.

In October 2025, a partial decipherment of the writing system has been proposed, identifying the language of the writing as proto-Corachol-Nahua, an early form of an Uto-Aztecan language.

On April 20, 2026, a gunman shot and killed a Canadian woman and wounded several others before killing himself at the pyramids.