Itzcoatl ( Classical Nahuatl: Itzcōhuātl [it͡sˈkoːwaːt͡ɬ] , "Obsidian Serpent", ) was the fourth king of Tenochtitlan, ruling from 1427 (or 1428) to 1440, the period when the Mexica threw off the domination of the Tepanecs and laid the foundations for the eventual Aztec Empire.
Itzcoatl was an illegitimate son of tlàtoāni Acamapichtli and an unknown Tepanec woman from Azcapotzalco. He was elected as the king when his predecessor, his nephew Chimalpopoca, was killed by Maxtla of the nearby Tepanec āltepētl (city-state) of Azcapotzalco. Allying with Nezahualcoyotl of Texcoco, Itzcoatl went on to defeat Maxtla and end the Tepanec domination of central Mexico.
Itzcoatl next turned his attention to the chinampas districts on the south shores of Lakes Xochimilco and Chalco. Fresh water springs lining these shores had allowed the development of extensive raised gardens, or chinampas , set on the shallow lake floors. Successful campaigns against Xochimilco (1430), Mixquic (1432), Cuitlahuac (1433), and Tezompa would secure agricultural resources for Tenochtitlan and, along with the conquest of Culhuacan and Coyoacán, would cement the Triple Alliance's control over the southern half of the Valley of Mexico.
In 1439, Itzcoatl undertook a campaign outside the Valley of Mexico against Cuauhnahuac ( Cuernavaca).
According to the Florentine Codex, Itzcoatl ordered the burning of all historical codices because it was "not wise that all the people should know the paintings". Among other purposes, this allowed the Aztec state to develop a state-sanctioned history and mythos that venerated Huitzilopochtli.
Itzcoatl also continued the building of Tenochtitlan: during his reign temples, roads, and a causeway were built. Itzcoatl established the religious and governmental hierarchy that was assumed by his nephew Moctezuma I upon his death in 1440.
- The dominant ethno-political group within the later Aztec political sphere.
- Itzcoatl's mother is given as a Tepanec woman from Azcapotzalco ; see for example Aguilar-Moreno (2007, p. 39).
- Madrid Codex, VIII, 192v, as quoted in León-Portilla, p. 155. Note that León-Portilla finds Tlacaelel to be the instigator of this burning, despite lack of specific historical evidence.
- Based on the maps by Ross Hassig in "Aztec Warfare"