The Aztec were a people who, through military alliances with other groups, dominated central and southern Mexico from the 14th to the 16th century. After the death of Moctezuma II in 1520, the divisions and internal strife among the 38 tributary provinces and the fiercely independent peoples at the fringes of the Aztec Empire, made it easy for the Spanish conquistadors -- led by Hernán Cortés -- to defeat it in 1521.
The name Aztec is derived from a mythical homeland to the north called Aztlá¡n; the Aztec also called themselves the Mexica. Their language belongs to the Nahuatlan branch of the Uto-Aztecan family. (Ancient History.com)