In the Post Classic period (900-1519 CE), the valley was a complex linguistic mosaic with speakers of at least four languages, Matlatzinca, Mazahua, Otomi, and Nahuatl . Aztec mythology mentions Matzalinco in stories related to their migration to the Valley of Mexico, and probably refers to Nahuatl speakers who settled in the Toluca Valley in the 13th century. Five towns in the valley are mentioned more than once in native histories: Cuahuacan, Malinalco, Matlazinco, Teotenanco, and Xilotepec, indicating that they were important settlements from well before the Aztec conquest.