Disease shaped the fall of the Aztec Empire, and the smallpox epidemic of 1520 was one of the most important factors in the Spanish victory. The indigenous population of the Americas had no immunity to the diseases brought by the Europeans, and the epidemics that followed the Spanish arrival devastated the indigenous populations. The Mexica state was particularly affected by the epidemics, and the death of key leaders and the demoralization of the population made it difficult for the Mexica to mount an effective resistance to the Spanish.
The First Epidemic (1520)
The first major epidemic struck in 1520, when smallpox was introduced to the Mexica state by the Spanish. The disease had arrived in the Americas with the Spanish, and it had been spreading across the Caribbean and the mainland since 1518. The first cases in central Mexico were reported in September 1520, when a Spanish expedition from Cuba brought the disease to the coast.
The epidemic spread rapidly through the indigenous population, and it killed a large proportion of the people who were infected. The Mexica capital of Tenochtitlan was particularly hard hit, and the disease killed perhaps 40 percent of the population of the city, including many of the leaders. The emperor Cuitláhuac, who had replaced Moctezuma II after his death in 1520, was one of the victims, and his death in late 1520 was a major blow to the Mexica resistance.
The Subsequent Epidemics
The first epidemic was followed by several others in the succeeding decades, and each took a heavy toll on the surviving population. A second major epidemic struck in 1521, just as the Spanish were laying siege to Tenochtitlan, and it killed many of the Mexica warriors and leaders. A third epidemic struck in 1526, and it killed perhaps a third of the population of the surviving indigenous communities. A fourth epidemic struck in 1545, and it was followed by a fifth in 1559 and a sixth in 1576.
The cumulative effect of these epidemics was catastrophic. The indigenous population of central Mexico, which had been perhaps 25 million on the eve of the Spanish conquest, had fallen to perhaps 2 million by the mid-seventeenth century. The collapse of the population was one of the great demographic catastrophes of world history, and it fundamentally altered the social and cultural landscape of the Americas.
The Biological Causes
The indigenous population of the Americas had no immunity to the diseases brought by the Europeans, and the diseases spread rapidly through the indigenous communities. The most important of these diseases was smallpox, which was the most lethal of the European diseases in the Americas. Other important diseases included measles, influenza, diphtheria, typhus, and various other infections.
The biological reasons for the severity of the epidemics in the Americas are not entirely clear, but several factors played a role. First, the indigenous population had no prior exposure to the European diseases, and they had not developed any immunity to them. Second, the indigenous population lived in large, dense communities, which facilitated the spread of the diseases. Third, the disruption of the agricultural and economic systems caused by the Spanish conquest made the indigenous population more vulnerable to the diseases.
The Impact on the Conquest
The epidemics had a major impact on the Spanish conquest of the Mexica state, and they helped the Spanish in several ways. First, the epidemics killed many of the Mexica leaders and warriors, and they weakened the Mexica resistance. Second, the epidemics demoralized the surviving population, and they made it difficult for the Mexica to maintain the social and political cohesion that was necessary to resist the Spanish. Third, the epidemics created a shortage of labor, and the Spanish were able to take advantage of this shortage to extract labor and tribute from the surviving population.
The epidemics also had an impact on the Spanish. The Spanish, who had some immunity to the European diseases, were less affected by the epidemics, and they were able to take advantage of the situation. The Spanish were also affected by the epidemics, however, and many of the conquistadors died of disease as well as in battle. The combination of military force and disease was devastating to the indigenous population, and it was a key factor in the Spanish victory.
Related Articles
- Spanish Conquest and Fall of the Aztec Empire — the broader context
- When did the Spanish conquer Tenochtitlan? — the chronology
- Who was Cuitláhuac and how did he lead the resistance? — the Mexica resistance
- The Spanish Conquest and Hernán Cortés — the campaign
- Indigenous Resistance After the Fall of Tenochtitlan — the aftermath
- History of the Aztec Civilization — the broader history