Note: Do not rely on this information. It is very old.
NahuaNahua, the primitive stock, whence are supposed to have sprung the historic and civilised peoples of the Mexican (Anahuac) plateau: Toltecs, pyramid-builders, 6th century; Chichimecs, 11th century, probably not originally Nahuas, but absorbed by them in 14th century; Aztecs, 15th century, founders of the last Nahua empire, with capital Mexico, overthrown by Cortes (1520-21). Branches of the Aztecs were the confederate Acolhuas, capital Tezcuco, and Tepanecs, capital Tlacopan. These and all others speaking the pure Aztec (Mexican) language claimed to be true Nahuas. The group does not comprise the Miztecs, Zapotecs, and other civilised peoples of Mexico who were not of Aztec (properly Nahuate) speech. The full form of the word is Anal-huate ("Amid-the-Waters"), in reference to the flooded depressions of the plateau round which were settled the original Nahua peoples.
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