To the art of war the Aztecs--a military nation who won and held all they possessed by force of arms--attached great importance. Training in the army was rigorous, and the knowledge of tactics displayed appears to have been very considerable. Although the Aztecs had founded and adopted from other nations a complete pantheon of their own, they were strongly influenced by the ancient sun and moon worship of Central America. _Ometecutli_ (twice Lord) and _Omecihuatl_ (twice Lady) were the names which they bestowed upon these luminaries, and they were probably the first deities known to the Aztecs upon their emergence from a condition of totemism. The sun was the _teotl_, _the_ god of the Mexicans, but it will be seen in the course of this chapter that the national deities and those acquired by the Aztecs in their intercourse with the surrounding peoples of Tezcuco and Tlacopan somewhat obscured the worship of those elementary gods. Through all the confusion of a mythology second only in richness to those of Egypt and Hellas can be traced the idea of a supreme creator, a 'god behind the gods.' This was not the sun, but an Allfather, addressed by the Mexican nations as 'the God by whom we live'; 'omnipotent, that knoweth all thoughts, and giveth all gifts'; 'invisible, incorporeal, one God, of perfect perfection and purity.' The universality of this great being would seem (as in other mythologies) to have led to the deification of his attributes, and thus we have a pantheon in which we can trace all the various attributes of an anthropomorphic deity. This subdivision of the deity was not, however, responsible for all the gods embraced by the Mexican pantheon. Many of these were purely national gods--and two at least had probably been raised to this rank from a condition of symbolic totemism during a period of national expansion and military success. Such a god was the Mexican Mars, Huitzilopochtli, a name which signifies 'Humming-bird on the left,' a designation concerning the exact derivation of which there is considerable difference of opinion. The general explanation of this peculiar name is that it may have arisen from the fact that the god is usually represented as having the feathers of a humming-bird on the left foot. Before attempting an elucidation of the name, however, it will be well to examine the myth of Huitzilopochtli.