Around 1200 AD, the Aztecs (Mexica) migrated into the Mexican Valley from the north. They discovered Teotihuacan lying abandoned—a city empty for roughly 600 years. Multiple tribes already in the valley repeatedly expelled them before they finally settled.
Key facts corrected:
- Teotihuacan fell around 550–650 AD, making it empty for approximately 550–650 years by 1200 AD, not 1,000 years

