Aztecs lived throughout the area now known as Central America. The Aztec capital city was Tenochtitlan, which was in the area of modern-day Mexico City.
The Aztecs called themselves the Mexica. They originally came from a place called Aztlan, though historians debate about exactly where this was located. They roamed throughout the 12th century in what is now Mexico, eventually settling around Lake Texcoco. The Tepanecs expelled them from the region, and the Mexica settled Tizapan with permission from Cocxtli, who was the leader of a people known as the Culhuacan. From there, the Mexica settled Tenochtitlan, which is modern-day Mexico City. The Aztecs expanded quickly during the 14th and 5th centuries, building canals and settling much of modern-day Mexico.
Cortez arrived on the Yucatan peninsula on 1519, and this was the beginning of the end for the Aztec Empire. Prior to his arrival, there was a series of natural disasters, including severe floods, in Tenochtitlan. A comet appeared in the sky as well, which was thought to be a symbol of doom. Cortes allied himself with enemies of the Aztec known as the Tlaxcala and conquered the Aztec capital city in 1521. Cortes renamed the city Mexico City, and hung the emperor.