The Mexica (Nahuatl: Mēxihcah, [meːˈʃiʔkaʔ]; the singular is Mēxihcatl [meːˈʃiʔkat͡ɬ]) or Mexicas — were an indigenous people of the Valley of Mexico, known today as the rulers of the Aztec empire.The Mexica were a Nahua people who founded their two cities Tenochtitlan and Tlatelolco on raised islets in Lake Texcoco around AD 1200.