Tenochtitlan in 1325 AD

Tenochtitlan and Lake Texcoco in 1519 before it fell to the Spanish

The greatest empire of Mesoamerica, the Aztecs, developed in the Valley of Mexico where modern-day Mexico City is located. 

Aztecs were driven out of their previous home in Culhuacan and roamed central Mexico for a place to settle. In 1325 AD, they found an island in the middle of Lake Texcoco. There, they saw an eagle perched on a cactus with a snake in its mouth. They believed this was a sign from the gods that this was where they would live and founded the city of Tenochtitlan. 

Tenochtitlan was the center of the Aztec government and religion. It was also a very big trading center. When the Spanish arrived in 1519, they guessed that 60,000 people came to the market in Tenochtitlan every day. People bought and sold many things there, including slaves (prisoners of war from states the Aztecs had taken over). The entire city was decorated with art, architecture, and stone sculptures.

Aztecs built islands on the water and used the natural resources available to them to grow crops. Tenochtitlan was an incredibly well-planned and built city. The Aztecs built causeways, bridges, and canals to travel to and from the city. At its peak, it housed around 400,000 people.  

In 1521 AD, the Aztec Empire was conquered by Spanish conquistadors. Believing that he was the god Quetzalcoatl, the Aztec emperor Montezuma II welcomed Spanish conquistador Hernan Cortez, who later turned the Triple Alliance against the Aztecs and took over Tenochtitlan.