La Noche Triste: The bloody night that changed the Aztec Empire forever

The Aztec Empire in the early 1500s exerted control over central Mexico thanks to military force that was by collecting regular tribute.

Its capital city, Tenochtitlán, sat on an island in Lake Texcoco, with stone temples, raised causeways, and a network of canals, and Moctezuma II held power as Huey Tlatoani, a title that meant Supreme Ruler. 

Across the Atlantic, Spain had begun its campaign of expansion in the Americas.

King Charles I specifically supported ventures into the New World, and explorers returned with stories of riches and civilisations more advanced than any previously encountered in the Caribbean.

In 1519, Hernán Cortés launched an unauthorised expedition from Cuba. He brought approximately 500 to 600 soldiers, along with horses, small cannon, and translators.

Among the most important of these was Malintzin, who was also called Doña Marina, who had an remarkable talent for languages and planning.

She also advised Cortés on diplomacy and regional politics, which allowed him to exploit divisions among Indigenous groups. 

Cortés began his march inland by forming shaky alliances with Indigenous groups.

Some, like the Totonacs, had grown tired of Aztec demands and offered support.

Others, including the Tlaxcalans, joined after initial conflict turned into cooperation.

Their knowledge of the terrain and regional politics became vital to Spanish success, as it allowed them to navigate unfamiliar territory with greater confidence. 

When the Spanish reached Tenochtitlán in November 1519, Moctezuma allowed them into the city and provided them with a palace for lodging.

Historians still debate his reasons for doing this. Some suggest he believed Cortés fulfilled a prophecy about the god Quetzalcoatl, while others argue that he wanted to avoid war until he better understood the newcomers.

Regardless, Cortés wasted little time and took Moctezuma hostage and he held him as a puppet so that Spanish commands were issued through him. 

Tensions increased over the following months as Aztec citizens grew restless.

Spanish interference with sacred sites, their greed for gold, and their attempts to impose foreign customs created a sense of sense of being betrayed.

The situation increased quickly, and by mid-1520, violence became inevitable. 

While Cortés marched out of Tenochtitlán to confront a rival Spanish force under Pánfilo de Narváez, he left Pedro de Alvarado in charge.

Alvarado soon committed a serious mistake during the Tóxcatl festival on 22 May 1520.

Since rumours had spread of a planned Aztec attack, he ordered an early attack on nobles gathered at the Templo Mayor.

They had assembled to honour Tezcatlipoca through sacred song and dance in one of the most important ceremonies of the Aztec religious calendar.

The Spanish attacked suddenly and they killed many unarmed celebrants, filling the temple courtyard with bodies. 

The massacre triggered an immediate uprising. Enraged warriors surrounded the palace where the Spanish had barricaded themselves.

Stones, arrows, and spears flew through the air as thousands of fighters demanded justice for the slain.

When Cortés returned to the city after defeating Narváez and absorbing his forces, he found Tenochtitlán in open rebellion. 

Moctezuma tried to speak to the crowds from a rooftop, urging them to stand down.

His words failed to calm the mob, and he died shortly afterwards. Some sources claimed that he was struck by stones thrown by his own people.

Others stated that the Spanish killed him after losing faith in his usefulness. As a result, the precise cause of his death remains uncertain. 

Cortés now faced a city in revolt, cut off from the mainland by broken causeways and patrolled waters.

Aztec canoes swarmed the lake, and supply lines had been severed. The Spaniards had little food, their weapons had worn down, and their morale had collapsed.

Cortés decided to abandon the city in the middle of the night, hoping stealth would help them escape with their lives. 

Shortly before midnight on 30 June, the Spanish began their escape from the city using the western causeway that led to Tlacopan.

This was one of only three major routes connecting the city to the mainland, and it had been partially destroyed.

Soldiers carried looted gold and jewels in heavy sacks, but they moved silently through the shadows as they crossed makeshift bridges over damaged causeways.

Rain fell steadily and it soaked their armour and it turned the path into slippery mud. 

Aztec warriors launched their ambush as soon as the retreat began. They attacked from canoes and from the edges of the causeway and they cut down those who tried to flee.

As the alarm spread, the city erupted into a deafening uproar that descended into violent assaults.

Arrows and javelins rained down on the Spanish and their allies, while obsidian-bladed clubs struck with deadly force in close combat. 

Many soldiers drowned as they stumbled into the gaps in the causeway and sank under the weight of their treasure.

Indigenous allies fell in massive numbers as well, especially the Tlaxcalans, who had supported the Spanish from the early stages of the campaign.

Horses were dragged into the water or slain where they stood. Artillery was abandoned.

Spanish formations collapsed in the darkness, and panic spread along the line of retreat. 

Cortés barely survived. His horse was wounded, and he reportedly lost control of the army.

At one point, he stopped beneath a large ahuehuete tree, later known as El Árbol de la Noche Triste, and wept.

Though some dismissed the story as romantic legend, Spanish sources mentioned that he broke down when he saw the extent of the disaster.

Nearly half his army, estimated at around 400 to 600 Spaniards, had been lost in a single night, along with thousands of Indigenous allies. 

Cortés led the survivors across the valley toward Tlaxcala, where his allies gave them food, shelter, and time to recover.

Wounded soldiers received care, and reinforcements arrived over the following weeks, which meant that the Spanish began to rebuild their strength.

Cortés wrote reports to Charles I of Spain in his Cartas de Relación, in which he framed the disaster as a temporary setback and requested further support.

He planned a renewed assault on Tenochtitlán and decided to destroy the empire completely. 

Meanwhile, the Aztec Empire also suffered. Cuitláhuac, who succeeded Moctezuma, ruled for approximately 80 days before dying of smallpox.

The disease, introduced by Europeans, swept through the population, killing thousands and undermining their military strength.

Cuauhtémoc became the next ruler and he tried to unite the people and fortify the city, but his efforts came too late to stop the coming siege. 

By May 1521, Cortés had returned to the Valley of Mexico, and he brought brigantines that were built to control the lake, along with thousands of Indigenous warriors, and a better understanding of Aztec tactics.

The subsequent siege of Tenochtitlán lasted for 93 days. Water supplies became undrinkable after the Spanish severed aqueducts leading into the city, and food quickly ran out.

The Spanish bombarded the city street by street until they found only ruin. 

On 13 August 1521, Cuauhtémoc finally surrendered. The Spanish burned the city and began to build Mexico City on its remains.

So, while La Noche Triste had ultimately revealed the limits of Spanish power, it also strengthened their resolve.