Hueyi Tlatoani in the context of "Tetzcoco (altepetl)"

The Spanish conquest of the Aztec Empire was a pivotal event in the history of the Americas, marked by the collision of the Aztec Triple Alliance and the Spanish Empire, with the latter being supported by its Indigenous allies. Taking place between 1519 and 1521, this event saw the Spanish conquistador Hernán Cortés, and his small army of European soldiers and numerous Indigenous allies, overthrowing one of the most powerful empires in Mesoamerica.

Led by the Aztec ruler Moctezuma II, the Aztec Empire had established dominance over central Mexico through military conquest and intricate alliances. Because the Aztec Empire ruled via hegemonic control by maintaining local leadership and relying on the psychological perception of Aztec power—backed by military force—the Aztecs normally kept subordinate rulers compliant. This was an inherently unstable system of governance, as this situation could change with any alteration in the status quo. A combination of factors including superior weaponry, strategic alliances with oppressed or otherwise dissatisfied or opportunistic Indigenous populations, and the impact of European diseases contributed to the downfall of the short rule of the Aztec civilization. In 1520, the first wave of smallpox killed 5–8 million people.