an unlikely candidate because Proto-Nahuan did not enter Mesoamerica until around the time of the fall of Teotihuacan (c. 600 AD), and that Totonac or Mixe–Zoque are likely candidates because many Mesoamerican languages have borrowed from these two languages during the Classic period. Others find Mixe–Zoque an unlikely candidate because no current Mixe–Zoque settlements are found in central Mexico. Around 500–600 CE a new language family entered Mesoamerica when speakers of Proto-Nahuan, a southern Uto-Aztecan language, moved south into central Mexico. Their arrival, which coincides with the decline of Teotihuacan and a period of general turmoil and mass migration in Mesoamerica, has led scientists to speculate that they might have been involved somehow in the fall of the Teotihuacan empire. What is known is that in the years following Teotihuacan's fall Nahuan speakers quickly rose to power in central Mexico and expanded into areas earlier occupied by speakers of Oto-Manguean, Totonacan and Huastec. During this time Oto-Manguean groups of central Mexico such as the Chiapanec, Chorotega and Subtiaba migrated south some of them reaching the southern limits of Mesoamerica in El Salvador and Nicaragua. Also some speakers of Nahuan moved south, some settling on the coast of Oaxaca where their speech became the language Pochutec, and others moving all the way to El Salvador, becoming the ancestors of the speakers of modern Pipil. Postclassic period (1000–1521 CE) In the Postclassic period Nahuan languages diversified and spread, carried by the culture commonly known as Toltec. In the early Postclassic period feuds between royal lineages in the Yucatán Peninsula caused the forefathers of the Itza' to move south into the Guatemalan jungle. In northwestern Oaxaca speakers of Mixtec and Chocho-Popolocan languages built successful city-states, such as Teotitlan del Camino, which did not fall under Nahuan subjugation. Speakers of Otomian languages (Otomi, Mazahua and Matlatzinca) were routinely displaced to the edges of the Nahuan states. The Otomi of Xaltocan, for example, were forcibly relocated to Otumba by the early Aztec empire. As Nahuatl, carried by the Toltec and later the Aztec culture, became a lingua franca throughout Mesoamerica even some Mayan states such as the Kʼicheʼ Kingdom of Qʼumarkaj adopted Nahuatl as a prestige language. In Oaxaca Zapotec and Mixtec peoples expanded their territories displacing speakers of the Tequistlatecan languages slightly. During this time the Purépecha (Tarascans) consolidated their state based at Tzintzuntzan. They were resistant to other states of Mesoamerica and had