The Aztec were a MesoAmerican group. They controlled parts of Mexico from the 14th to the 16th century.
At first, the Aztec were a nomadic tribe. In 1325, they arrived in the Valley of Mexico and founded their capital of Tenochtitlán. Over the next two hundred years, they conquered other tribes of central Mexico. This made them a powerful cultural and political group.
In 1521, Hernán Cortés, along with Spanish troops and native allies, conquered Tenochtitlán. The Spanish then founded Mexico City on the ruins of the Aztec capital.
Most of what we know about Aztec history and culture is from studying archaeological evidence and records kept by the Spanish conquistadors.