Chief among the Aztec gods was Huitzilopochtli (hwit-zil-oh-POHCH-t'lee), though they also worshiped a number of others, including Quetzalcoatl. In fact, the world's largest monument is a temple to Quetzalcoatl (see box, "The Quetzalcoatl Pyramid"). All of these deities required human sacrifice, which the Aztecs practiced with more frequency —and more cruelty—than any other Mesoamerican peoples.
Of course the accusation of cruelty would have meant nothing to the Aztecs; theirs was not a society that put a premium on mercy or kindness to the weak. It was common for an Aztec priest to cut the heart out of a living person. Nor were victims only drawn from enemy armies: Aztec warriors considered it an honor to be chosen as a sacrifice to the gods, and in one year alone, more than 20,000 people met their end on the altars of Huitzilopochtli. The Aztecs often ate the flesh of the sacrificed victim, and sometimes priests would flay (skin) a body and dance in the skin.
A prominent feature of Teno-chtitlan was its skull racks, on which the priests displayed the skulls of sacrificed victims as a sign of the peoples' devotion to the gods. Like the Maya, the Aztecs used two calendars, and the first day of the fifty-third year, when the two came into alignment, required a special sacrifice called the New Fire Ceremony. After cutting out the victim's heart, the priest would build a fire in the open chest cavity to symbolize the continuance of life for the Aztec people.