Cortes and the Conquest of Mexico
Leaving Cuba, February 1519
In February 1519, Hernan Cortes sailed from Santiago de Cuba with around 500 men, 16 horses and 14 cannon. Diego Velazquez, the governor of Cuba, had originally commissioned the expedition but tried to recall it at the last minute, suspecting Cortes would not stay loyal once he had reached the mainland. Velazquez was right. From the moment Cortes landed at Vera Cruz on the Mexican coast in April 1519, he was operating outside Velazquez’s authority — technically, in defiance of his governor. To make sure his men could not change their minds, Cortes scuttled most of his ships at Vera Cruz, deliberately stranding the expedition on the mainland. (He did not, despite the legend, burn them.)
Cortes left Santiago de Cuba in February 1519 with around 500 men, 16 horses and 14 cannon, defying his governor Velazquez. He scuttled (not burned) his ships at Vera Cruz to commit his men to the inland march.
The Aztec Empire in 1519
The state Cortes was about to challenge was not a fragile kingdom. The Aztec or Mexica Empire of central Mexico ruled from the lake city of Tenochtitlan (population 200,000+, larger than any city in Spain) and extracted tribute from millions of subjects across modern-day Mexico. Its emperor was Montezuma II, a senior priest-king. Its religion required regular human sacrifice. But its empire had been built by force, not consent: the tribute peoples around its edges, including the independent state of Tlaxcala, had grown to hate Aztec rule. Cortes did not bring down the Aztec Empire on his own; he weaponised the resentment its subjects already felt.
The Tlaxcalan Alliance
After landing, Cortes marched inland with his small Spanish force and a translator he had been given as a slave: La Malinche (also called Dona Marina). She spoke both Nahuatl and a Mayan language; combined with Geronimo de Aguilar, a Spaniard who spoke Mayan after years of captivity, she gave Cortes a route into Aztec politics. The Tlaxcalans, who were not subjects of the Aztecs and resented their tribute demands, fought a brief war with Cortes in September 1519 — and then accepted alliance with him. Tens of thousands of Tlaxcalan warriors would fight on the Spanish side for the next two years.
No. The historian Matthew Restall’s ‘Seven Myths of the Spanish Conquest’ calls this the central myth of the period. The conquest was not a few hundred Spaniards crushing the Aztec Empire. It was a coalition war, with the Tlaxcalans — tens of thousands of Indigenous warriors — doing the bulk of the fighting alongside a Spanish core. Spanish steel, horses, gunpowder and crossbows mattered, but they did not decide the war on their own. Smallpox, Aztec internal divisions, the resentment of tribute peoples and Cortes’s political skill all mattered more. Top-band judgement answers reject the ‘Cortes the genius’ framing and weigh these factors against each other.
Cortes Meets Montezuma
In November 1519, Cortes was welcomed into Tenochtitlan by Montezuma II. The Spanish were given a palace to stay in and treated as honoured guests — though they were also, effectively, surrounded. Within weeks, Cortes seized Montezuma in his own palace and held him as a hostage, ruling the empire through him. Whether Montezuma genuinely believed Cortes was the returning god Quetzalcoatl is a Spanish-source claim that modern historians like Camilla Townsend doubt — the prophecy story may have been invented after the conquest by Mexica nobles trying to explain a defeat. What is certain is that Spanish behaviour, including a massacre at the temple festival of Toxcatl in May 1520 led by Cortes’s deputy Pedro de Alvarado, ended any chance that the occupation could remain peaceful.
La Noche Triste, 30 June 1520
A full Aztec uprising broke out. On the night of 30 June 1520 — remembered by the Spanish as La Noche Triste, ‘the Sad Night’ — the Spanish tried to escape Tenochtitlan along its causeways under cover of darkness. They were attacked from all sides. Montezuma had already died on 29 June (whether by Spanish guards or Aztec stones is disputed), and Cortes lost more than half his force, much of his treasure and most of his cannon. The Spanish stumbled out into Tlaxcalan territory, broken but alive. They had been driven from Tenochtitlan in catastrophe.
Smallpox in Tenochtitlan, Autumn 1520
In the autumn of 1520, smallpox arrived in Tenochtitlan with a captured Spanish soldier — and devastated the city. Cuitlahuac, the new emperor who had led the resistance on the Noche Triste, died of the disease after only 80 days on the throne. The Aztec leadership, military command, priests and ordinary people died together; survivors had to walk over bodies in the streets. By the time Cortes returned to besiege the city in 1521, the empire he was attacking had already lost a substantial portion of its population and most of its experienced commanders. Disease — not skill at arms — bought the Spanish coalition the time it needed to regroup.
Smallpox struck Tenochtitlan in autumn 1520 and killed the new Aztec emperor Cuitlahuac after just 80 days on the throne. The epidemic destroyed Aztec leadership and weakened the city before the final siege began.
The Siege of Tenochtitlan, 1521
Cortes spent the winter rebuilding. In Tlaxcala, Spanish carpenters and Tlaxcalan workers built thirteen brigantines — small armed sailing ships — in pieces, then carried them in sections over the mountains to Lake Texcoco and assembled them. Tens of thousands of Tlaxcalan warriors joined a Spanish core of around 700 men. From May 1521 the brigantines blockaded Tenochtitlan’s causeways while the coalition cut off the city’s aqueducts, food and water. The last Aztec emperor, Cuauhtemoc, organised a fierce defence street by street.
The city fell on 13 August 1521. An estimated 100,000 Aztec defenders and civilians died in the siege; Tenochtitlan itself was systematically demolished and the new colonial capital, Mexico City, was built on its ruins. Cuauhtemoc was captured trying to escape across the lake. He was kept alive for several years before being executed by Cortes in 1525 on a march through Honduras — a quiet, lawless killing that sealed the political end of the Mexica imperial line.
The strongest answers weigh several factors against each other rather than collapsing the conquest into one cause. The Tlaxcalan alliance provided most of the warriors and local intelligence. Smallpox killed the Aztec leadership at the worst possible moment. The empire’s tribute system had alienated subject peoples, who defected to Cortes’s coalition. Spanish steel, horses, crossbows and brigantines mattered — especially on the lake — but were not decisive on their own. La Malinche’s linguistic and political skill made the alliance possible. Cortes’s leadership was real but cannot stand alone. The Restall view is that this was a coalition victory over a fractured empire, not a Spanish miracle.
After the Fall
Cortes was made first Governor and Captain-General of New Spain in 1523, but the Crown distrusted independent conquistadors. By 1528 he had been recalled to Spain, given titles and estates but stripped of the governorship; the bureaucracy of the Casa de Contratacion, audiencia and (from 1535) viceroyalty took over. The lesson the Crown learned from Cortes was the same one it had learned from Columbus: conquistadors were too dangerous to leave in charge of conquered territory.