The Aztecs were a Mesoamerican civilization that flourished in central Mexico from approximately 1300 to 1521. The population consisted of various ethnic groups from the region, with a particular emphasis on those who spoke the Nahuatl language. While the term is often associated specifically with the Mexica people of Tenochtitlan, it more broadly refers to the Nahua polities and peoples of central Mexico during both the pre-Hispanic and Spanish colonial eras.
Aztec culture was organized into city-states known as altepetl, which frequently formed alliances or political confederations. In 1427, a significant empire was established as a confederation of three primary city-states: Tenochtitlan, Tetzcoco, and Tlacopan.