When the Spanish arrived in the Aztec capital, they had several goals. Interestingly enough, the Spanish were lucky to be alive when the entered the Aztec capital. Normally, the Aztecs captured and killed their invaders. However, the Aztecs thought the Spanish were sent by the Aztec god Quetzalcoatal to save the Aztec people. Thus, they were spared. The goals of the Spanish were quite straightforward. They had come to the region looking to convert people to Christianity and to find gold. They Spanish were amazed to see how much gold there was in the Aztec capital.
Eventually the Spanish left, with some encouragement from the Aztecs, who were beginning to doubt the Spanish were sent by the Aztec god. However, the Spanish were going to return. When they returned, they were prepared to conquer the Aztecs and take their gold. They certainly accomplished this goal upon return.