The bow and arrow was an extremely common hunting tool in virtually every culture, and was adopted for warfare in Central Mexico by at least the 12th century AD.
The bow and arrow became a popular and extremely common weapon in many Mesoamerican armies during Aztec times. The earliest evidence of the bow’s presence in Mesoamerica coincides with the arrival of the Nahuatl speaking migrants from the north, suggesting that the original Aztec migration was responsible for its spread to the rest of Mexico.
The Aztecs’ extensive use of the bow is attested to in many Spanish sources, with Bernal Diaz del Castillo noting that many Spaniards mistook the thousands of arrows that showered their position for swarms of locusts. Another encounter he describes occurred when the Spanish were besieged inside Moctezuma’s palace in Tenochtitlan. Aztec soldiers launched hundreds of arrows, as well as stones and spears, through the palace windows until the spent ammunition covered the entire floor.
The bow complimented the sling and atlatl as a ranged weapon, and was best at medium ranges. Slings could typically be thrown quicker and had greater range, but lacked the accuracy and penetration of an arrow. Atlatls were more powerful, as the projectile was much larger and heavier, but they lacked the range of the bow. In addition, bows were more effective than either of the two when attempting to fire over an obstacle such as a large city wall, building, or pyramid.
The exact bow tactics of the Aztec army are largely unknown, but some guesswork can be made as to their use and deployment on the battlefield. Spanish sources heavily suggest that arrows were fired in volley, which would have had a significant moral shock to a target, and made it far easier to direct the archers’ fire. How exactly their fire was directed is not known, but a decently drilled force could accomplish this with relative ease.
Bernal Diaz described the bows as very large, as tall as a man in many cases. This is not necessarily indicative of their draw-weight, but their use in war suggests that they were probably significantly more powerful than a hunting bow. The bows themselves were constructed of various kinds of wood and strung with animal sinew (likely deer).
The Aztecs used various types of arrows including flaked obsidian, barbed fish-bone, fire hardened wood, etc. Fire arrows were occasionally used, but probably only offensively against a besieged city. Fire arrows are plagued with numerous deficiencies such as decreased speed and range, and lessened penetration, and were therefore reserved for setting a defending position alight.
The Aztec elite loathed the bow and preferred the atlatl instead. As such, commoners alone used the bow in battle. Although the elite were far better trained and would have excelled at using the bow, commoners made up the majority of the army so this loss was largely mitigated.
In several cases, however, this cultural trend in the Aztec military played heavily against them. Both the Tarascans and Tlaxcalans utilized the bow to great extent throughout their armies. The fact that their elite, heavily trained, veteran soldiers utilized the bow in battle gave them a decisive defensive advantage. This is part of what slowed the Aztec conquests of Tlaxcala, and it certainly played a role in the decisive defeat of Axayacatl’s army in their battle with the Tarascans.