The Spanish Conquest of the Aztecs, 1519–21

Reports of riches discovered by Spanish expeditions to Yucatán in 1517 played a role in turning the attention of Spanish colonists in Cuba, including Hernán Cortés, the mayor of Santiago de Cuba, toward Mexico. Cortés began preparing an exploration and trading expedition to Mexico under the sponsorship of Cuban Gov. Diego Velásquez de Cuéllar. When Velásquez changed his mind and withdrew his support, however, Cortés set out on an unauthorized rogue expedition in February 1519 with 11 ships, 508 soldiers, about 100 sailors, and 16 horses. The conquistadors, fighting for gold, God, and glory, sought to expand Christianity while acquiring wealth, land, and political power. The crown of Castile supported expeditions of these soldiers of fortune with its weapons, flag, and political clout, but not its coffers. The leader of an expedition could only petition the crown for support if they were willing to stake their own fortunes on the expedition’s success. These conquistadors and company were not an official army, received no pay as such, and stood to gain wealth only through their own efforts at exploitation.

The beginning

During a brief interlude in Tabasco, where he stayed for a time in order to gain intelligence from the local Indigenous people, Cortés received presents from them, including 20 women, one of whom, Marina (“Malinche”), became his mistress and interpreter and bore him a son, Martín.

Cortés set up a base camp at Veracruz and secured an alliance with the Totonac people. He then set out for the Mexican interior, relying sometimes on force, sometimes on amity toward the local Indigenous peoples. As he crossed through Tlaxcala, Cortés shrewdly exploited the existing political crisis within the Aztec empire; the Aztecs were bitterly resented by many of the subject peoples who had to pay tribute to them. The nation of Tlaxcala, although independent of the Aztecs, was in a state of chronic war with the Aztec emperor Montezuma II. After fighting a series of battles with Cortés’s men, the Tlaxcaltecs ultimately forged an alliance with the Spaniards, and several thousand Tlaxcaltecs joined Cortés’s men on their march to Mexico.

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As an experienced soldier and statesman, the ninth Aztec emperor, Montezuma, had proven his abilities by expanding the Aztec empire and gaining tributes from previously unconquered surrounding nations. In fact, the Aztec empire was still expanding when its growth was halted in 1519 by the appearance of Spanish explorers. Rejecting all of Montezuma’s threats and blandishments to keep him away from Tenochtitlán or Mexico, the capital (rebuilt as Mexico City after 1521), Cortés entered the city on November 8, 1519, with his small Spanish force and only 1,000 Tlaxcaltecs. In accordance with the diplomatic customs of Mexico, Montezuma received him with great honor. Cortés soon decided to seize Montezuma in order to hold the country through its monarch—believing that the Aztecs would not attack as long as he held Montezuma captive—and achieve not only its political conquest but its religious conversion.

Montezuma’s submission to the Spaniards, however, had eroded the respect of his people. According to Spanish accounts, he attempted to speak to his subjects and was assailed with stones and arrows, suffering wounds from which he died three days later. The Aztecs, however, believed the Spaniards had murdered their emperor, and Cortés’s force was nearly destroyed as it tried to sneak out of Tenochtitlán at night.

The Spanish eventually returned, and in May 1521 Cortés and his army mounted an attack, known as the Battle of Tenochtitlán, on the Aztec capital. With a force numbering more than 800 conquistadors and tens of thousands of Indigenous warriors, they were able to launch assault after assault against the Aztecs. By this time, smallpox and other contagious diseases brought to the continent by the Europeans had begun to spread among the Aztecs, reducing their capital city’s population by 40 percent in 1520 alone. Disease had significantly weakened Tenochtitlán’s ability to withstand Cortés’s siege, and the Europeans eventually wore the Aztec warriors down and broke through the city’s defenses, slaughtering the Aztecs and destroying the city. Cortés claimed the city on August 13. Over the next three years the conquistadors brought the whole of Mesoamerica under Spanish rule.

Factors in Spanish success

Some scholars have argued that among the reasons for the success of the Spanish conquest of the Aztec empire was that Montezuma, at least initially, suspected that Cortés was a returning god. Historians long held that the Aztecs had feared and expected the return of an important deity—Quetzalcóatl, the white, bearded god who would rule over the empire—and that the white, bearded Cortés was aware of this fear and used it to his advantage in his expedition across Mexico. Some 21st-century historians, however, questioned not only whether the Aztecs thought Cortés was a god but whether the legend of Quetzalcóatl was really a part of the Aztecs’ belief system. They suggested the well-known version of this story was a Spanish creation that was subsequently incorporated into Aztec lore.

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Traditional accounts of the Spanish conquest point to the Spaniards’ and the Aztecs’ divergent concepts of war and the technological superiority of Cortés’s European weapons to explain the decisive Spanish victory. In addition to those factors, scholars have also identified disease as a significant factor influencing the fall of the Aztecs. Prior to their contact with Europeans, Indigenous peoples in the Americas had likely developed a tolerance for the limited range of pathogens to which they had been exposed in their relative isolation, such that their populations were devastated by smallpox and other contagious diseases delivered by conquistadors.

“Had there been no epidemic, the Aztecs, their war-making potential unimpaired and their warriors fired with victory, could have pursued the Spaniards, and Cortés might have ended his life spread-eagled beneath the obsidian blade of a priest of Huitzilopochtli,” writes Alfred Crosby, who coined the term ecological imperialism in 1986 to describe the devastation wrought on Indigenous civilizations by the diseases, invasive plants and animals, and agricultural practices that colonizers brought to the Americas.