The Aztec believed that four worlds had existed before the present universe. Those worlds, or "suns," had been destroyed by catastrophes. Humankind had been entirely wiped out at the end of each sun. The present world was the fifth sun, and the Aztec thought of themselves as "the People of the Sun." Their divine duty was to wage cosmic war in order to provide the sun with his tlaxcaltiliztli ("nourishment"). Without it the sun would disappear from the heavens. Thus the welfare and the very survival of the universe depended upon the offerings of blood and hearts to the sun, a notion that the Aztec extended to all the deities of their pantheon. The first sun was called Nahui-Ocelotl, "Four-Jaguar," a date of the ritual calendar. Humankind was first destroyed by jaguars. The animal was considered by the Aztec as the nahualli ("animal disguise") of the creator god Tezcatlipoca.

At the end of the second sun, Nahui-Ehécatl, "Four-Wind," a magical hurricane transformed all people into monkeys. That disaster was caused by Quetzalcóatl (the Feathered Serpent) in the form of Ehécatl, the wind god.

A rain of fire had put an end to the third sun, Nahuiquiahuitl, "Four-Rain." Tlaloc as the god of thunder and lightning presided over that period.

The fourth sun, Nahui-Atl, "Four-Water," ended in a gigantic flood that lasted for 52 years. Only one man and one woman survived, sheltered in a huge cypress. But they were changed into dogs by Tezcatlipoca, whose orders they had disobeyed.

Present humanity was created by Quetzalcóatl. The Feathered Serpent, with the help of his twin, Xólotl, the dog-headed god, succeeded in reviving the dried bones of the old dead by sprinkling them with his own blood. The present sun was called Nahui-Ollin, "Four-Earthquake," and was doomed to disappear in a tremendous earthquake. The skeleton-like monsters of the west, the tzitzimime, would then appear and kill all people.

Two deeply rooted concepts are revealed by these myths. One was the belief that the universe was unstable, that death and destruction continually threatened it. The other emphasized the necessity of the sacrifice of the gods. Thanks to Quetzalcóatl's self_sacrifice, the ancient bones of Mictlan, "the Place of Death," gave birth to men. In the same way, the sun and moon were created: the gods, assembled in the darkness at Teotihuacán, built a huge fire; two of them, Nanahuatzin, a small deity covered with ulcers, and Tecciztécatl, a richly bejeweled god, threw themselves into the flames, from which the former emerged as the sun and the latter as the moon. Then the sun refused to move unless the other gods gave him their blood; they were compelled to sacrifice themselves to feed the sun.