From sources of the time, historians can explain how Cortes was able to conquer the Aztecs for various reasons. In combination these reasons allowed him to have the upper hand in the conquest of Mexico. To begin with the Aztecs had a harsh tribute system that was not popular among the people of Mexico, and this tribute system allowed Cortes to befriend many tribes; meaning supplies were easily accessible. Furthermore, the Spanish brought diseases into South America that they were immune to but the Aztecs were not. The spread of diseases such as small pox reduced the Aztec population and furthered Cortes' success. There was also La Malinche; a tribal girl given as a gift to Cortes. She proved invaluable in translating local dialects in combination with Geronimo de Aguilar, went on to become Cortes’ mistress. An important aspect of the success was due to Montezuma's belief that Cortes was Quetzalcoatl, a Mesoamerican deity, which made him wary of offending Cortes. Another predominant reason for the Spanish success was due to their weaponry such as their armour and firepower. Finally, Cortes' Indian allies such as the Tlaxcalans made up the majority of his combined army, and helped in battles. All these reasons worked together to allow Cortes, originally with 508 men, to conquer the Aztec Empire of millions of people.
To begin with, the Aztec's forced tribute system allowed Cortes to act as a liberator. The process of human sacrifice was extremely common and was feared by the majority of the common people. As the majority of those who were sacrificed were war captives who opposed the Aztecs, they obviously greatly feared the brutal tribute system. Cortes was disgusted at the thought of human sacrifice, and this allowed him to gain Indian allies as well as gain respect among Mexican tribes that feared and opposed the Aztecs, Most of the local population feared