A group of ancient cultures located in modern day Mexico. Often the term "Aztec" refers exclusively to the Mexica people of Tenochtitlan (now the location of Mexico City), situated on an island in Lake Texcoco, who referred to themselves as Mexica Tenochca.
The Aztec people were certain ethnic groups of central Mexico, particularly those groups who spoke the Nahuatl language and who dominated large parts of Mesoamerica in the 14th, 15th and 16th centuries, a period referred to as the late post-classic period in Mesoamerican chronology.
In 1521, in what is probably the most widely known episode in the Spanish colonization of the Americas (also known as "La Conquista"), Hernan Cortes, along with a large number of Nahuatl speaking indigenous allies, conquered Tenochtitlan and defeated the Aztec Triple Alliance under the leadership of Hueyi Tlatoani Moctezuma II; In the series of events often referred to as "The Fall of the Aztec Empire".
Subsequently the Spanish founded the new settlement of Mexico City on the site of the ruined Aztec capital.