The aztecs believed that a great white warrior god was to come to them and bring them blessings and prosperity.they thought cortes was this man-god hence they trusted him completely ; add this to oppots answer. Whhandyman.
There were several factors, which led to the defeat of the Aztec empire in the hands of Hernan Cortes and his army of 500 men. Although the Aztec empire was a highly flourishing empire with all kinds of riches and prosperity, nevertheless they were not as shrewd and sapient as were their Spanish rivals.
In the initial phases of their 'visit', Hernan Cortes and his army were clever enough to never gave any reason for the Native Americans of the Aztec empire to believe that they were here to conquer the Aztec empire. Nevertheless the Aztecs were mistaken in their comprehension of the motives of Hernan Cortes and his men. Another reason besides the naiviette of the Aztec empire was the technological development, which accoutered the Spanish army.
In comparison the Aztecs did not have any technology to fight the war that led finally to their defeat. Moreover the third reason that led to the defeat of the Aztecs were the diseases that the Spanish men brought with them, which were unfamiliar to the Native Americans and led to many deaths in the Aztec empire and ultimately to their defeat.
Tactic were very powerful to the Aztec