Final answer:
Fray Bernardino de Sahagún's historical accounts suggest complex motivations for the Spanish attack on the Mexica, including strategic alliances and the introduction of smallpox, which contributed to the fall of Tenochtitlán.
Step-by-step explanation:
Fray Bernardino de Sahagún's accounts provide insight into the complex motivations behind the Spanish attack on the Mexica people during a religious festival. Hernán Cortés and his forces were not simply superior in arms, but also took advantage of existing strife within the Aztec Empire. Many indigenous groups, such as the Tlaxcalans, resented Aztec rule and allied with the Spanish, contributing to the conflict's outcome. Additionally, the introduction of smallpox by the Europeans played a significant role in weakening the Mexica, as did the utilization of superior weaponry and military tactics by the Spaniards.
The Spanish may have chosen to attack during a festival to capitalize on the element of surprise and to target the Mexica leadership. It's unlikely the Aztecs foresaw the attack, as the festival was a sacred occasion and the participants were unarmed. The attack left hundreds dead, sowing chaos and weakening the positions of the Mexica elites. The unintended introduction of smallpox created a crisis, and the Spaniards utilized this to cement their military and political dominance, eventually leading to the fall of Tenochtitlán and the subsequent renaming of the city to Mexico City.