The Tepanecs formed a culture with political, social and military organization; settled in Azcapotzalco, they dominated minor villages establishing their culture in Coyoacan around 1332 CE.
In the early 15th century, Tezozomoc brought the Tepanec to their height of power; at that point they controlled nearly all of the Valley of Mexico as well parts of the Toluca and Morelos valleys.
Tepanec |
When Maxtla laid siege to Tenochtitlan in 1428, Chimalpopoca's successor and uncle, Itzcoatl, repelled his forces with the aid of an alliance of city states, including Texcoco under Nezahualcoyotl and many former Tepanec allies, notably Tlacopan.
The coalition conquered Acolman and Otumba, sacking them only due to the sudden Tepanec siege of Tenochtitlan and Tlatelolco.