One of the activities always present in the history of the ancient Mexicas is war. Whether it was to increase territory, secure taxes or seize captives for sacrificial rites, war was a necessary mechanism underpinning social and cosmic functioning, since man, when defeating the enemy, collaborated with the gods in revitalizing the world. This sacred principle was expressed verbally and iconographically through atl-tlachinolli o teoatl tlachinolli – “water and hearth” – two currents of opposing elements whose primordial and antagonistic powers are brought together to create time, space and life.
The oppositional nature of atl-tlachinolli is seen in its colors. The yellow/red branch, crowned with a flower or a butterfly, symbolizes the fiery forces coming from fire and the Sun. Its counterpart, atl, is colored blue, and depicted with precious jewels or sea conches, which symbolize water. The struggle between fire and water reflects the same dynamic between other oppositional pairs: hot/cold, Sun/Moon, man/woman, and many more. The warlike and symbolic value of this pairing holds a central place in their cosmovision and can be traced through many esthetic, mythological and religious realms.
The warlike destiny of the Mexicas is inscribed in the myth of the eagle (fire-Sun) landing on the nopal cactus (water-Moon). Even more, the birth of Huitzilopochtli, patron god of the Mexicas, reinforces this connection: he is born armed and ready to defeat his sister and brothers, the goddess Coyolxauhqui and the Centzon Huitznáhuac. This battle has cosmic implications related to the movement and alternation of opposites, since it is fought by the solar god, fiery and hot, and nocturnal forces, cold and aquatic (the Moon and the stars).
In myth and in historical battles, war was considered to be a sacred activity associated with human sacrifice, which nourished the Sun with the blood of the enemy. The dual and antagonistic principle of atl-tlachinolli is reflected as well in other aspects of human life, such as in the sexual act and pregnancy, considered to be a battle between hot and cold forces, whose goal is to keep life in the world.