Final answer:
Before the Aztecs, various complex societies thrived in the Valley of Mexico, including those of the Woodland period and later the Pueblo civilizations. These societies developed agricultural practices, social structures, and architectural achievements before undergoing declines or transformations.
Step-by-step explanation:
The societies which preceded the Aztecs in the Valley of Mexico reflect a rich history prior to the Aztecs' rise to power. One of the earliest complex societies in what would become Mexico are those associated with the Woodland period, dating from around 1000 BCE. This period marks the transition from nomadic hunter-gatherer lifestyles to more settled agricultural communities, although it is not the immediate precursor to the Aztec civilization.
Later, in the first millennium CE, significant settlements and civilizations such as the complex Pueblo societies—including the Mogollon, Hohokam, and Anasazi—flourished in the region before the Aztecs. Additionally, the city at Cahokia and the Eastern Woodland peoples reflected the divergence and complexity of societies in pre-Columbian North America. These cultures featured elements such as developed agriculture, social divisions, and monumental architecture. However, many of these societies were in decline or had significantly transformed by the time the Aztecs began to establish dominance in the Valley of Mexico.