How Tenochtitlan Fell — The Alliances That Changed the Conquest

How Tenochtitlan fell was shaped by alliances that changed the conquest. In 1521, a Spanish led coalition of Indigenous fighters, workers, and engineers turned a retreat into a siege of the Mexica capital. The Tlaxcalans first fought Cortés’s forces, then joined them for their own reasons. After the Spaniards were driven from Tenochtitlan in 1520, allies helped Cortés regroup and prepare to return. In Texcoco, Indigenous workers built 13 brigantines and dug a canal about 9,100 feet long to float them into Lake Texcoco. Historian Kristian J. Fabian discusses an estimate of 40,000 people working on the canal. For nearly three months, allied forces pressed along the causeways while the brigantines attacked across the lake and helped cut supply routes. Smallpox had killed ruler Cuitláhuac in December 1520, and Cuauhtémoc led the city as the siege closed in. Tenochtitlan fell on August 13, 1521. Spanish chronicles center Cortés, while Nahua accounts preserve the devastation experienced by the people under attack. Together, these accounts show how a coalition with different aims changed the balance of power and the course of the conquest. Sources: • Kristian J. Fabian, “Masters of the Land: Native Ship and Canal Building During the Spanish-Aztec War” (2023): https://www.researchgate.net/publication/3... • UNAM, “Especial México 500. La fuerza indígena en la caída de Tenochtitlan” (2021): https://ciencia.unam.mx/leer/1141/especial... • Library of Congress, “General History of the Things of New Spain by Fray Bernardino de Sahagún: The Florentine Codex. Book XII: The Conquest of Mexico” (1577): https://www.loc.gov/resource/gdcwdl.wdl_10...