By Emilia Wellesley · Published May 5, 2026 · Updated May 6, 2026
What Was the Expedition of Hernán Cortés?
The expedition of Hernán Cortés was a Spanish military and diplomatic campaign that ran from February 1519 to August 1521 and ended with the fall of Tenochtitlán, capital of the Mexica (Aztec) empire. Cortés sailed from Cuba against the orders of his governor, landed near present-day Veracruz with about five hundred and fifty men, gathered indigenous allies who outnumbered the Spanish twenty to one, and besieged a city larger than any in contemporary Europe. The conquest was decided as much by smallpox, Tlaxcalan strategy, and the translator Malintzin as by Spanish steel.
The campaign survives in two contradictory archives. On one side sit Cortés’s self-justifying letters to Charles V and Bernal Díaz del Castillo’s old-age memoir Historia Verdadera. On the other sit the Nahuatl testimonies preserved in the Florentine Codex, the indigenous annals of Tlaxcala, and the documentary trail in the Archivo General de Indias in Seville. What follows traces the campaign as the evidence allows, within the broader landscape of historical and archaeological mysteries.
The 1519 Veracruz Landing
Cortés left Cuba on 18 February 1519 in eleven ships with around five hundred and fifty Spanish soldiers, sixteen horses, and a small number of African men, both enslaved and free. His commission from the governor of Cuba, Diego Velázquez, was exploratory; he was recalled before he could sail and sailed anyway. The legal fiction that justified the rest of the campaign was assembled at Veracruz: the soldiers founded a town, elected a council, and elected Cortés its captain-general, theoretically severing his authority from Velázquez and binding it directly to the Crown [1].
Scuttling, Not Burning, the Ships
The most familiar story from this phase is the one that did not quite happen as told. Cortés is said to have burned his ships to prevent retreat. The contemporaneous record, including his second letter to Charles V and Spanish accounting documents in Seville, is clear that the ships were stripped, beached, and scuttled — hulls breached so they sank in shallow water — but not set on fire. The image of burning ships enters the literature in the late sixteenth century and likely owes more to classical rhetoric than to a Veracruz beach. The point of the gesture survives: Cortés removed the means of return with a hatchet, not a torch [2].
Malintzin Enters the Record
At Potonchán in March 1519 Cortés received twenty enslaved women as part of a peace settlement with the local Maya. One of them, baptized Marina and known to the Mexica as Malintzin, spoke both Yucatec Maya and Nahuatl, the language of the Mexica court. With the Spanish priest Jerónimo de Aguilar, who had been shipwrecked years earlier and learned Yucatec Maya, she became the linguistic bridge through which every diplomatic conversation of the campaign passed. Camilla Townsend, in her 2006 study Malintzin’s Choices, has argued that Malintzin should be read not as a passive translator but as a strategic actor whose decisions about phrasing, omission, and emphasis shaped the campaign’s diplomacy [3]. The Florentine Codex consistently shows her standing beside Cortés in scenes where Spanish accounts place him alone.
The March to Tenochtitlán and the Tlaxcalan Alliance
From the coast Cortés moved inland through territory governed by Mexica tributaries. Most of these polities resented Tenochtitlán’s demands for tribute and sacrificial victims, and several — Cempoala on the coast, then the larger Tlaxcalan confederation — judged an alliance with the strangers might settle accounts with the city in the lake.
The Tlaxcalan Decision
Tlaxcala first fought the Spanish. In a series of battles in September 1519 the Tlaxcalan commander Xicotencatl the Younger inflicted heavy casualties on the Spanish column. The Tlaxcalan senate then deliberated for several weeks and chose alliance over continued resistance. The terms recorded in the Tlaxcalan annals, discussed at length by Hugh Thomas in his 1993 work Conquest: Montezuma, Cortés and the Fall of Old Mexico, gave the Spanish food, lodging, route guidance, and eventually thousands of warriors, against future privileges within whatever order replaced the Mexica empire [4]. From this point onward the campaign was a coalition operation, and at the final siege Tlaxcalan and other indigenous soldiers outnumbered Spaniards by something like fifty to one.
The Cholula Massacre
In October 1519 the column reached Cholula, a sacred Mexica-allied city. What happened there is contested. Cortés’s letter says his Tlaxcalan allies discovered a planned ambush and the Spanish struck first; the Mexica account in the Florentine Codex describes a calculated massacre of unarmed nobility in the city’s main plaza. Matthew Restall, in Seven Myths of the Spanish Conquest (2003), reads the event as more political theater than military necessity, signaling to the Mexica that the Spanish-Tlaxcalan coalition was willing to violate the conventions of Mesoamerican diplomacy [5].
Tenochtitlán, Moctezuma, and La Noche Triste
The Spanish-Tlaxcalan column entered Tenochtitlán on 8 November 1519 along the southern causeway. Moctezuma II met Cortés at the city’s edge and lodged him in the palace of his father Axayacatl. What followed across the next eight months is one of the strangest episodes of the campaign and the one most distorted in retelling.
Moctezuma’s Captivity
Within a week of entering the city Cortés placed Moctezuma under what the Spanish called protective custody — effectively a hostage in his own palace. The Spanish narrative presents this as voluntary submission, citing a speech in which Moctezuma reportedly recognized Cortés as the heir of an ancient prophecy. The Nahuatl sources do not describe such a speech. Townsend has argued that the prophecy framing was assembled retroactively from fragments of the Quetzalcoatl tradition and Spanish messianic literature [3]. For eight months the emperor governed under Spanish supervision while Cortés sent treasure shipments back to the coast.
The Massacre at the Templo Mayor and La Noche Triste
In May 1520 Cortés left Tenochtitlán to confront a Spanish force Velázquez had sent from Cuba to arrest him. He defeated that force at Cempoala and absorbed its men. In his absence his lieutenant Pedro de Alvarado, fearing an uprising, ordered an attack on Mexica nobles celebrating the festival of Toxcatl in the precinct of the Templo Mayor. The Florentine Codex preserves a detailed account written within a generation by Nahua informants. The city rose. Cortés returned to a siege of his own quarters. On the night of 30 June 1520, attempting to evacuate along the Tlacopan causeway under cover of darkness, the Spanish lost between four hundred and six hundred men, much of the looted treasure, and Moctezuma — killed earlier, by Spanish or Mexica hands, the sources disagree. The Spanish remembered the night as la noche triste. From the Mexica perspective it was a victory.
Smallpox, the Siege, and the Fall of the City
What turned the Spanish defeat at Tenochtitlán into the Mexica defeat of 1521 was not, primarily, a return of Spanish strength. It was an epidemic.
The 1520 Smallpox Epidemic
Smallpox arrived in central Mexico with an enslaved African man named Francisco Eguía, brought ashore in April 1520 with the Velázquez expedition Cortés had defeated at Cempoala. The disease moved through the Valley of Mexico in the second half of 1520, killing what historians estimate at thirty to forty percent of Tenochtitlán’s population within months. The new emperor Cuitláhuac, who had organized the resistance during la noche triste, died of the disease in early December 1520 after a reign of about eighty days. His successor Cuauhtémoc inherited a city that was hungry, sick, and short of leadership. Smallpox did not cause the conquest, but it removed the demographic and military margin the Mexica had used to expel the Spanish [4].
The 1521 Siege
From late December 1520 Cortés rebuilt his coalition in Tlaxcala, supervised the construction of thirteen brigantines for use on Lake Texcoco, and severed Tenochtitlán’s three causeways one by one. The siege ran from 22 May to 13 August 1521. The brigantines, hauled overland and assembled on the lake, gave the besiegers control of the water and cut the city’s food supply. The fighting moved street by street; the defenders under Cuauhtémoc contested every causeway and every plaza for seventy-five days. Cuauhtémoc was captured on 13 August 1521 attempting to flee across the lake by canoe. The city he had defended held a population larger, by most estimates, than contemporary Paris or Constantinople. By the time the Spanish entered, much of it was rubble; the canals ran with corpses; the survivors were starving.
Was the Conquest Inevitable or Contingent?
The older account treats the Spanish triumph as inevitable: superior weapons, horses, steel, the inadvertent biological weapon of European disease, and a providential narrative in which a small disciplined force overcomes a primitive empire. The newer account, advanced by Restall, Townsend, and the indigenous-perspective historiography of the last forty years, treats the conquest as contingent on a list of accidents — Malintzin’s linguistic gift, the Tlaxcalan senate’s vote, the timing of the smallpox wave, Moctezuma’s miscalculation in admitting the Spanish to the city, the Velázquez expedition that brought the disease ashore [5]. Neither framing is wholly wrong. The Spanish brought advantages the Mexica could not counter on the timescale they had; they also depended at every stage on indigenous allies, translators, strategy, food, and political legitimacy. The empire fell because a coalition of its tributaries decided a Spanish-led order might serve them better than a Mexica-led one. That decision was not foreordained.
What the Record Will Not Tell Us
Several questions remain genuinely open: the conversation in which Moctezuma agreed to lodge the Spanish in Axayacatl’s palace; the circumstances of his death in late June 1520, with Spanish accounts blaming a stone thrown by his own subjects and Nahua accounts blaming Spanish swords; the population of Tenochtitlán at contact, estimated from one hundred and fifty thousand to over three hundred thousand; and the fate of the Mexica treasury lost in the canals. The Archivo General de Indias holds the Spanish-Crown perspective; the Florentine Codex preserves the indigenous one. The two archives do not agree about all of the same events. They agree that the city fell, that the people of the lake were no longer the people of the lake afterward, and that what replaced them was something the participants of 1519 could not have foreseen.
Frequently Asked Questions
When did the expedition of Hernán Cortés take place?
The expedition ran from February 1519, when Cortés sailed from Cuba, to 13 August 1521, when Tenochtitlán fell to a Spanish-Tlaxcalan-Texcocan coalition. Major phases were the Veracruz landing (April 1519), the Tlaxcalan alliance (September 1519), the entry into Tenochtitlán (8 November 1519), la noche triste (30 June 1520), and the seventy-five-day siege (22 May to 13 August 1521).
Did Hernán Cortés really burn his ships?
No. The contemporaneous record, including Cortés’s second letter to Charles V and Spanish accounting documents in Seville, shows the ships were stripped, beached, and scuttled in shallow water in summer 1519 — hulls breached so they could not be refloated. The image of burning ships enters the literature decades later as classical-rhetorical embellishment.
Who was Malintzin (La Malinche)?
Malintzin, baptized Marina and later called La Malinche, was an enslaved Nahua woman given to the Spanish at Potonchán in 1519. She spoke Nahuatl and Yucatec Maya, and with Jerónimo de Aguilar she translated every diplomatic conversation of the campaign. Camilla Townsend’s Malintzin’s Choices (2006) argues she should be read as a strategic actor.
What role did the Tlaxcalans play?
A decisive one. After initial battles in September 1519 the Tlaxcalan senate chose alliance with the Spanish, and from that point Tlaxcalan warriors outnumbered Spaniards in every major engagement. At the 1521 siege the ratio was approximately fifty indigenous allies to every Spaniard. Hugh Thomas’s Conquest (1993) treats the alliance as the campaign’s central enabling condition.
How did smallpox affect the conquest?
Smallpox arrived in central Mexico in April 1520 with the Velázquez expedition Cortés defeated at Cempoala. It killed an estimated thirty to forty percent of Tenochtitlán’s population within months, including the emperor Cuitláhuac after a reign of about eighty days. It did not by itself cause the conquest, but it removed the demographic margin the Mexica had used to expel the Spanish on la noche triste.
What is the Florentine Codex?
A twelve-volume Nahuatl-Spanish encyclopedia of Mexica life compiled in the 1570s under the Franciscan Bernardino de Sahagún with Nahua collaborators. Book Twelve is the indigenous account of the conquest, written within a generation of the events. It is the principal counterweight to Cortés’s letters and Bernal Díaz’s memoir.
Was the conquest of Mexico inevitable?
The newer historiography, advanced by Matthew Restall and Camilla Townsend, treats it as contingent on accidents — Malintzin’s linguistic gift, the Tlaxcalan vote for alliance, the timing of the smallpox wave, the Velázquez expedition that brought the disease ashore. The older view treats Spanish technological and biological advantages as decisive. Both readings have evidence; neither alone explains the campaign.
Where can the expedition be studied today?
The Archivo General de Indias in Seville holds Cortés’s letters and the viceregal correspondence; the Biblioteca Medicea Laurenziana in Florence holds the Florentine Codex. Hugh Thomas’s Conquest (1993), Matthew Restall’s Seven Myths (2003), and Townsend’s Malintzin’s Choices (2006) are the standard modern entry points.
