They took this sighting as a sign from the gods that this was their new home. The once nomadic tribe had found their new residence on Lake Texcoco and started to construct temples and settlements. The Aztecs quickly expanded their empire by increasing their economy through agriculture and military conquests. By 1519, their tribe had turned into one of the world's greatest civilizations and Tenochtitlan was one of the biggest cities in the world at the time. In the Aztec religion, they practiced human sacrifice rituals. For their practice, they waged war with nearby areas only to capture people to use as sacrifices. As they started to bring in people from their nearby conquests, they began to tax more frequently. While the working and poor had to pay taxes, the nobles did not, which started to create anger and resentment. The Aztecs introduced taxes to the new territories they conquered. The Aztecs gained most of their wealth through these taxes, which the Spanish perceived as a weakness and a way to destroy the empire. When the Aztecs conquered new lands around them, they imposed taxation through metals, stones, enslaved people, and