The Aztecs left Aztlan, their ancestral homeland, primarily due to a combination of environmental, social, and religious factors. According to Aztec mythology, their god Huitzilopochtli commanded them to leave Aztlan in search of a new home. This divine instruction was a significant motivator for their migration.
Environmental challenges, such as resource scarcity and unfavorable living conditions, also played a crucial role. Aztlan, often described as an island or a place surrounded by water, may have faced issues like flooding or drought, making it difficult to sustain the population.
Social pressures, including conflicts with neighboring tribes and internal strife, further compelled the Aztecs to seek a new territory. The journey led them to the Valley of Mexico, where they eventually established their capital, Tenochtitlan, fulfilling the prophecy of finding an eagle perched on a cactus with a snake in its beak.
In summary, the Aztecs left Aztlan due to a combination of divine guidance, environmental hardships, and social conflicts, which collectively pushed them to migrate and establish a new civilization.