Excerpts from Books and Wikipedia
"The Aztec people, who called themselves 'Mexica,' moved into what is now central Mexico from the north in the thirteenth century; . . . but the Aztecs played second fiddle to the city-state of Azcapotzalco, which dominated the whole region and with which they were obediently allied. . . . The Aztecs and their allies were now the dominant power in central Mexico. Itzcoatl was succeeded in 1440 by Moctezuma, and the Aztecs went on to build up an empire that, by the time Cortes and Spaniards arrived in 1519, covered approximately 75,000 square miles (194,000 sq km) Moctezuma ruled a population of between five and six mill people. It seems that Aztec gods had a consuming appetite for human bodies. Victims were sacrificed in the thousands to Huitzilopochtli and the other Aztec deities, and their flesh was eaten as a kind of communion with these deities." [1001 Days]