The Mexica placed themselves at the end of a sequence. Four previous worlds, each with its own sun, had been created and destroyed; the present one, the fifth sun, was made at Teotihuacan when the gods gathered in darkness and one of them threw himself into a fire to become the sun. In the versions recorded after the conquest the new sun would not move until the other gods gave themselves too. Motion, and therefore time, began with an act of self-destruction.
From this followed a relationship of debt. The gods had spent themselves to make the world habitable, and human beings, made in these accounts from the bones of an earlier creation and from blood a god drew from his own body, owed a return. That return was made in offerings of many kinds: incense, food, flowers, quail, paper, and blood drawn by the worshipper from earlobes, tongue or limbs with maguey spines and obsidian blades. Autosacrifice of this sort was routine, expected of priests daily and of ordinary people at intervals, and it is the context in which the killing of captives belongs rather than a separate category.
The pantheon was large and its members overlapped. Huitzilopochtli, the Mexica patron, was a solar and warrior god of no great antiquity outside their own history. Tlaloc, the rain god, is attested in central Mexico for well over a millennium before them, which is the point of the twin summit of the main temple: the newcomer beside the god of the land. Tezcatlipoca, associated with fate, night, rulership and conflict, and Quetzalcoatl, the feathered serpent linked to wind, priesthood and creation, appear in the stories as rivals and as aspects of a single pattern.
Gods could also be worn. A priest or a victim dressed in a deity's regalia was treated as that deity present, which is a different relation from representation and does not translate easily.