The Aztec people dominated large parts of Mesoamerica from the 14th to 16th centuries, speaking Nahuatl. They formed the Aztec Triple Alliance centered around their capital of Tenochtitlan in the Valley of Mexico in the 13th century. Through alliances and conquests, the Aztecs established a tributary empire that expanded their political influence far beyond the valley. However, in 1521 the Spanish conquistador Hernan Cortes, aided by many Nahuatl allies, conquered Tenochtitlan and defeated the Aztec empire under Emperor Moctezuma II, establishing Mexico City on its ruins.