Smallpox and Indigenous Alliances, Not Firearms, Toppled the Aztec Empire

Around 1520, smallpox made its way to Mesoamerica, likely introduced by a Spanish relief mission, resulting in the deaths of millions in central Mexico. In Tenochtitlan, the disease claimed the life of Cuitláhuac, leaving Cuauhtémoc in charge. Historians consider this epidemic a crucial contributor to the empire's downfall, with fatalities exceeding those from warfare. Hernán Cortés arrived in 1519 with a small force, later joined by thousands of Tlaxcalan warriors. The Aztec Empire depended on military strength and tribute, forming a Triple Alliance with Tenochtitlan, Texcoco, and Tlacopan. Cortés captured Moctezuma II and besieged Tenochtitlan, which ultimately succumbed in August 1521 after nearly three months.