<human>:  When was Mexico City founded?
<bot>: Mexico City was founded in 1325 by the Aztecs. The Aztecs were an indigenous people of Mexico, who had settled in the Valley of Mexico, and who built the city of Tenochtitlan, which is now Mexico City. The Aztec Empire was a pre-Columbian empire that flourished in Mesoamerica from the 14th century to the 15th century. It was centered in what is now Mexico City.