The Fall of the Aztec Empire

In 1519, Spanish conquistador Hernán Cortés and his expedition entered the lands of the Aztec Empire in what is now Mexico. Less than two years later, the Aztec capital of Tenochtitlan fell to Spanish forces and their Indigenous allies.

How could such a powerful empire fall so quickly? The answer involves more than Cortés and his soldiers. Indigenous alliances, political rivalries, disease, military technology, and a long siege all contributed to the defeat of the Aztec Empire.

When Cortés arrived in 1519, the Aztec Empire was one of the most powerful states in the Americas. At its center was Tenochtitlan, a large city built on islands in Lake Texcoco. Historians estimate that hundreds of thousands of people may have lived in the city and surrounding area.

Tenochtitlan was connected to the mainland by raised roads called causeways. The city contained temples, palaces, markets, canals, gardens, and neighborhoods. Farmers used chinampas, raised areas of fertile soil built in shallow lake waters, to grow crops.

The Mexica were the leading power in an alliance with the cities of Texcoco and Tlacopan. Together, these cities controlled a large empire. Conquered communities were often required to provide tribute, including food, cloth, and valuable goods.

This system made the empire powerful, but it also caused resentment. Some communities opposed Aztec rule and were willing to form alliances against it.

Cortés left Cuba for Mexico in 1519 with several hundred soldiers, sailors, horses, weapons, and ships. His expedition sought wealth, territory, and greater Spanish influence. Spanish leaders also wanted to spread Catholicism.

Along the coast, Cortés encountered many Indigenous communities. Some fought against the Spanish, while others later formed alliances with them.

Communication was essential. Jerónimo de Aguilar, a Spaniard who had lived among Maya peoples, spoke a Maya language. Another important interpreter was an Indigenous woman named Malinalli, also known as Malintzin and later called Doña Marina.

Malinalli had been enslaved and was given to the Spanish along with other women. She spoke Nahuatl and a Maya language. Her knowledge of languages, politics, and local societies helped the Spanish communicate and negotiate with Indigenous leaders.

One of Cortés's greatest advantages was the support of Indigenous peoples who had their own reasons for opposing the Aztec Empire.

The Tlaxcalans were among the most important Spanish allies. At first, they fought Cortés's forces. Later, their leaders allied with the Spanish because they had long been enemies of the Mexica and wanted to weaken Aztec power.

Other communities also joined the campaign. Indigenous allies provided thousands of warriors, along with food, information, transportation, and knowledge of the land.

These alliances are essential to understanding the conquest. A few hundred Spaniards did not defeat the Aztec Empire by themselves.

Cortés and his allies reached Tenochtitlan in November 1519. The Aztec ruler Moctezuma II initially received the Spanish into the city.

Relations soon became tense. Cortés and his men took Moctezuma captive and attempted to use him to influence the city.

Later, Cortés left Tenochtitlan to confront a Spanish force sent to arrest him. While he was away, Pedro de Alvarado ordered an attack during an Aztec religious celebration, killing many participants.

When Cortés returned, fighting spread through the city. Moctezuma died during the conflict, although accounts disagree about exactly how he died.

In June 1520, the Spanish and many of their allies tried to escape Tenochtitlan. Aztec forces attacked them, killing hundreds. The survivors escaped and regrouped with their Indigenous allies.

The Aztec Empire had not yet been defeated.

Soon, smallpox spread through central Mexico.

The disease had been brought to the Americas through European colonization. Indigenous populations had never encountered the virus and had little biological resistance to it.

Smallpox killed large numbers of people in Tenochtitlan and nearby communities, including warriors, farmers, leaders, and other community members.

The epidemic weakened the city at a critical moment. Disease alone did not defeat the Aztec Empire, but it made resistance much more difficult.

In 1521, Cortés returned with Spanish soldiers and a much larger force of Indigenous allies.

The attackers surrounded Tenochtitlan and began a siege. A siege occurs when an army surrounds a city and tries to prevent food, water, supplies, and reinforcements from reaching the people inside.

The Spanish also built small armed boats to fight on Lake Texcoco. Their soldiers had steel swords, crossbows, guns, cannons, metal armor, and horses. These provided advantages in some types of fighting, but Spanish weapons alone did not determine the outcome.

The Aztec defenders fought fiercely for nearly three months. As the siege continued, food and clean water became scarce. Smallpox had already weakened the population.

On August 13, 1521, Tenochtitlan fell.

The fall of the Aztec Empire cannot be explained by one person or one advantage.

Cortés benefited from divisions that already existed within the empire. Indigenous nations such as the Tlaxcalans provided large numbers of warriors and important support. Smallpox devastated the population. Spanish weapons, horses, and military strategies added other advantages. The long siege also cut Tenochtitlan off from food, water, and supplies.

The Spanish victory did not mean Indigenous peoples disappeared. Communities continued to resist, negotiate, adapt, and preserve their languages and traditions under Spanish colonial rule.

After Tenochtitlan fell, the Spanish destroyed much of the city and began building Mexico City on and around its remains. Spain established colonial rule over much of the region, while Indigenous communities experienced major changes to their governments, lands, religions, and daily lives.

The conquest ended the Aztec Empire as an independent political power, but understanding how it happened requires looking beyond Cortés and recognizing the alliances, resistance, suffering, and survival of the many Indigenous peoples involved.