Why was Cortes able to overthrow Aztecs?

Hernán Cortés was able to overthrow the Aztecs due to a combination of superior military technology, strategic alliances, and the exploitation of local rivalries. He formed alliances with indigenous groups dissatisfied with Aztec rule, such as the Tlaxcalans, which provided him with additional troops. The Aztecs were also weakened by internal strife and the impact of European diseases, such as smallpox, which decimated their population. Cortés's tactical use of cavalry and firearms further gave him an advantage in battles against the Aztec forces.