Final answer:
The Spanish conquered the Aztecs with superior military technology like steel armor and weapons, and horses, alongside forging alliances with other local tribes. Smallpox introduction by the Spanish also played a critical role in weakening the Aztec resistance.
Step-by-step explanation:
One of the primary advantages that allowed the Spanish to intimidate and eventually defeat the Aztecs was their superior military technology and tactics. The Spanish, led by Hernán Cortés, were equipped with steel armor and steel swords, and also brought horses, which gave them a significant advantage over the Aztec forces, who fought with traditional weapons such as bows, arrows, and spears. Besides the military advantage, the Spanish forged alliances with local tribes that were previously subjugated by the Aztecs, like the Totonacs and the Tlaxcalans, who provided essential support against the Aztec Empire. However, one should not underestimate the devastating impact of smallpox, an infectious disease inadvertently introduced by the Spanish, which resulted in a massive loss of life within Tenochtitlán and weakened the Aztec resistance considerably.