The Battle of Tenochtitlán (1521 CE)

At the same time that the Ottomans were rising to power in modern day Turkey, the Aztec Empire was taking shape over 7000 miles away, in the part of the world now known as Mexico.

The Aztec capital was the magnificent city of Tenochtitlán, first established in approximately 1325 CE. This city sat on an island at the center of a deep, wide lake, with walkways running between the central city and the shore.

The city was probably home to as many as 350,000 inhabitants. In the rest of the world, only Paris, Venice and Constantinople would have had as many citizens as that at this time.

From their capital at Tenochtitlán, the Aztecs also ruled an empire of 500 neighboring tribes and states, which were home to roughly 6 million people. Some of these states were claimed through warfare, while others joined willingly.

The Aztecs practiced human sacrifice, which has given them a bloody reputation. However, their military conflicts were relatively bloodless.

In what the Aztecs referred to as ‘The Song of Shields’, a warrior would try to capture the enemy instead of killing them. These prisoners were taken back to Tenochtitlán, where some were sacrificed, while others were absorbed into Aztec society.

Everything changed for the powerful Aztecs in 1492, when Christopher Columbus stumbled across the Americas. Over the next few decades, thousands of Europeans traveled to the New World in search of riches, power and adventure.

One of these men was Hernan Cortés, an ambitious young Spanish conquistador who, according to his secretary, 'had little wealth, but much honor.' He rode a ship to Cuba at the age of 19, where he took a job as a government administrator.

The Cuban natives told their Spanish conquerors about a wealthy nation to the west. Hernan Cortés – now at the age of 33 – was given the task of exploring the region and finding out whether these rumors were true. In 1519 CE, he set sail for Mexico with 11 ships and just over 500 men.

When Cortés and his men arrived in Mexico, the first people they encountered were not the Aztecs, but the Totonacas – one of the subject states of the Aztec Empire.

The Totonacas were amazed by these strange arrivals, with their pale skins, explosive weapons and metal armor.

The Spanish rode horses, an animal which the Totonacas had never seen before. Some historians believe that the Totonacas thought that these riders were actually a single beast, half-man and half-horse.

The Totonacas introduced the Spanish to Gerónimo de Aguilar, a Spanish monk who had been shipwrecked in Mexico several years earlier, and managed to learn some of Totonacas' native language.

He helped Cortés to communicate with them, and the two sides realized that they shared a common goal: to overthrow the Aztec Empire.

The Totonacas brought the Spanish to speak with the Tlaxcalans, a more powerful state who had so far resisted being absorbed into the Aztec Empire. A tentative alliance was agreed, and the 500 Spaniards traveled to Tenochtitlán with the support of 6000 Tlaxcalan warriors.

In November 1519, Hernan Cortés and his allied forces of Spaniards and Tlaxcalans arrived at the gates of Tenochtitlán. The reigning emperor, Moctezuma II, did not respond with hostility; instead, he welcomed the Spanish into the city as honored guests.

Spanish historians later explained that Moctezuma saw Cortés as a white-skinned god, but this detail is probably untrue. In reality, he probably saw the diplomatic potential of allying with the Spanish, and did not want to offend them.

Whatever his reasons, his decision to invite the Spanish into the city was a mistake. The Spanish betrayed him, taking him hostage in his own palace, then demanding gold from his frightened subjects in return for the emperor’s life.

When the Spanish took Moctezuma hostage, Aztec warriors laid siege to the palace. In the confusion, the emperor was killed – historians don't know how it happened, but the Spanish probably panicked and ended his life.

They then tried to run from the giant city, carrying as much gold as they could carry. Weighed down by this treasure, hundreds of Spaniards were slain by the Aztecs in an event referred to as La Noche Triste, or ‘The Night of Sorrows’.

Hernan Cortés, and a handful of others, did manage to escape alive. And now that he'd tasted the riches of Tenochtitlán, he wanted to claim the entire city as his own. He spent the next two years strengthening his alliance with the Tlaxcalans, as well as recruiting other states and local tribes with personal vendettas against the Aztecs.

In 1521 CE, Cortés led an organized attack on the Aztec city, which later became known as the Battle of Tenochtitlán. His army consisted of almost a thousand Spaniards armed with cannons and explosives, plus tens of thousands of indigenous warriors. He cut off the city’s food and water, then launched attack after attack, wearing the Aztecs down.

After 93 days, the Aztec defense collapsed. The Spaniards surged into the city, destroying temples and burning districts, killing an estimated 100,000–240,000 Aztecs along the way.

The Spanish built a new city on the ruins of Tenochtitlán, which later became known as Mexico City. As for the native tribes who supported the attack, many of them found themselves dominated by the Spanish state. In some ways, all they'd done was swap the control of one powerful empire for another.

The first reports of the Battle of Tenochtitlán came from Cortés himself, who sent an account of his victory back to Spain. This report is comprehensive, but it probably digresses from the truth in a number of places, as he exaggerated his own contribution to the battle, while also glorifying some of his cruel behavior against Aztecs foes. Other Spaniards were similarly self-congratulatory.

But not all of them took this approach. Bartolomé de las Casas, a Christian priest, gave a very different account of this battle, as he sought to raise awareness of the atrocities committed by Spaniards like Cortés at the expense of native peoples: 'What we committed in the Indies stands out among the most unpardonable offenses ever committed against God and mankind.'

The natives also wrote their own accounts. Many of these were destroyed or amended by Spanish colonists, but a few survived. The Anales de Tlatelolco is a heartfelt recollection of the empire’s collapse compiled by anonymous Aztec authors. A poem about the battle describes how 'Broken spears lie in the roads; we have torn our hair in grief. The houses are roofless now, and their walls are red with blood.'

After the victory of the Spanish over the Aztec Empire, Europeans turned their attention to other parts of the Americas. In 1533 CE, a Spanish force led by Francisco Pizarro arrived in South America. Inspired by the tactics of Cortés, he destroyed the powerful Inca Empire, centered in modern day Peru, after assassinating the emperor and recruiting the support of local tribes.

These newly acquired American territories were rich in natural resources, and became a source of great wealth for the Spanish Empire. Many of the native peoples were enslaved, while Christian missionaries engaged in a process of mass conversion, wiping away any native religions and instituting Catholicism in their place.

Other European countries took the same approach in North America, with the English and the French taking vast swathes of land from the indigenous peoples, killing and indoctrinating millions of natives along the way. The modern Americas are the product of these changes, with countries all the way from Canada to Chile irrevocably changed by the touch of European hands.

If the Aztecs had defeated the allied forces of Hernan Cortés, so soon after the humiliation of ‘The Night of Sorrows’, the Europeans might have reevaluated their relationship with American civilizations. Rather than trying to conquer them by force, they might have taken a more cautious approach, trying to establish trade deals and build alliances.

As valuable trade partners to European nations, the American empires might have survived for hundreds of years, well into the modern age. Native cultures may have been allowed to endure, instead of being forcibly replaced by European alternatives. The most common language in Central America might have been Nahuatl, not Spanish, while the most common religion might have been Nahua, not Catholicism.

These native empires could have also played a role in major world events. For example, the Aztec Empire might have thrown their weight into World War One or World War Two, completely changing the course of these conflicts. All in all, the world could have been a very different place.

Having said all that, there's another important factor to consider in relation to the fall of the Aztecs: the role of European diseases. When the first Spaniards arrived in the Americas, they brought foreign diseases like smallpox, mumps and measles, to which the native people lacked a natural immunity. In some places, more than 90% of the local people were killed by European disease.

Because of this, some historians have questioned the significance of the Spanish victory at Tenochtitlán. Even if the Aztecs had won, these insidious diseases would have eaten away at their numbers, and the empire would probably have collapsed anyway. In the words of Diego Muñoz Camargo, a contemporary Spanish historian: 'There was no resisting.'

A single battle is capable of changing the course of history, but so are biological factors like plagues and diseases. If the Aztecs had been the ones carrying a devastating disease, and the Spanish had fallen victim to it, then the story of the Americas would have unfolded very differently.