In the 15th and early 16th centuries the Aztecs ruled a large empire in what is now central and southern Mexico.
The origin of the Aztec people is uncertain, but were probably a tribe of hunters and gatherers on the northern Mexican plateau before their appearance in Meso-America about the 12th century.

 The Aztec were successful in creating a great state and had a an advanced system of agriculture. They cultivated available land and built elaborate systems of irrigation.

Under the ruler Itzcóatl (1428-40), Tenochtitlán wwas friendly with neighboring states of Texcoco and Tlacopan. He became the dominant power in central Mexico. At its height, Tenochtitlán itself covered more than 5 square miles and had more than 140,000 citizens, making it the biggest city ever achieved by a Meso-American civilization.

Aztec religion shared many of the beliefs of earlier peoples, notably the Maya, such as that the Earth was the last in a series of creations and that it occupied a position between systems of 13 heavens and 9 underworlds.

Gods included Huitzilopochtli, god of war; Tonatiuh, god of the sun; Tlaloc, god of rain; and Quetzalcóatl, the Feathered Serpent, who was part deity and part culture hero

Human sacrifice, particularly by offering a victim's heart to the sun god and bloodletting were commonly practiced.

The Aztec calendar  had a solar year of 365 days and a sacred year of 260 days; the two yearly cycles running in parallel produced a larger cycle of 52 years.

The Aztec empire was still expanding when its progress was stopped in 1519 by Spanish explorers. The ninth emperor, Montezuma II was taken prisoner by Hernán Cortés and died in custody. When the Spanish capture of Tenochtitlán in 1521, the Aztec empire came to an end.