By the mid-1520s, Cortés was extending Spanish authority beyond Tenochtitlan into surrounding regions, using a mix of alliances, coercion, and violence against indigenous polities. These campaigns cemented Spanish colonial rule and set patterns of exploitation, disease, and demographic collapse that would devastate indigenous populations across the following century.
The years following the 1521 fall of Tenochtitlan were less a single dramatic conquest than a grinding, uneven process of Spanish expansion across a patchwork of independent indigenous states, some of which allied with the newcomers against rival powers, others of which resisted for years or decades.
Cortés relied heavily on Tlaxcalan and other indigenous allies who had their own reasons for opposing Aztec dominance, illustrating how the conquest was never simply Spaniards against a unified indigenous resistance but a complex civil and colonial war exploited by outsiders.
Disease proved a far deadlier conqueror than steel: smallpox and other Old World pathogens killed an estimated 80-90% of the indigenous population of central Mexico within decades, a catastrophe that made military resistance increasingly unsustainable even where it persisted.
Key people: Hernán Cortés