By the time the Spanish arrived the Basin of Mexico where Tenochtitlan and Teotihuacan are located, Teotihuacan had been largely abandoned for almost 900 years. A small remnant population lived on its outskirts after its abandonment in the late 500s/early 600s, but this population was never very large compared to the urban center and people never reoccupied the ceremonial center of the city.

During the Aztec period (1200 to 1650), approximately 12,000 to 14,000 people lived in the city-state territory with 4,000 to 5,000 people in the city itself. This city-state encompassed about 100 km2 and covered the middle region of the Teotihuacan valley. This city-state was incorporated into the Acolhua confederation, which largely controlled the eastern side of the Basin of Mexico, in 1409. The western side was controlled by the Tepanec confederation. In 1418, though, the Tepanecs defeated the Acolhua confederation, deposed the ruler of the Teotihuacan city-state, and put in place their own ruler. But Teotihuacan was only shortly controlled by the Tepanecs because in 1427 the Triple Alliance overthrew the Tepanecs and ruled the Basin until the arrival of the Spanish.

• Garraty, Christopher P. "Aztec Teotihuacan: political processes at a Postclassic and early Colonial city-state in the Basin of Mexico." Latin American Antiquity (2006): 363-387.