Why the Spanish Conquered the Aztec Empire: Gold, God, and Glory

The Spanish conquest of the Aztec Empire (1519–1521) was driven by the classic triad of early modern imperialism:

1. Economic Gain (Gold)

• Aztec tribute system accumulated vast gold, silver, jade, feathers, cacao, textiles.
• Cortés's expedition was a private venture funded by Cuban governor Velázquez; investors expected massive ROI.
• Mercantilist logic: bullion = national power.

2. Religious Zeal (God)

• Post-Reconquista Spain saw itself as Catholicism's defender.
• Papal bulls (Inter caetera 1493) mandated conversion.
• Aztec human sacrifice horrified Spaniards, providing moral justification for destruction of temples/codices.
• Franciscans, Dominicans, Augustinians followed conquistadors.

3. Political Power & Strategy (Glory)

• Aztec hegemony (Triple Alliance) blocked Spanish expansion inland from Veracruz.
• Cortés exploited internal divisions: Tlaxcalans, Totonacs, Texcoco factions allied with Spain against Aztec oppression.
• Personal ambition: Cortés defied Velázquez; sought title, land, legacy.

4. Exploitation of Labor & Resources

• Encomienda system granted conquerors indigenous labor/tribute.
• Silver mines (later Zacatecas, Potosí) required coercive labor systems.

Technological & Biological Factors

Steel, gunpowder, horses, dogs, and—decisively—smallpox (1520) which killed Emperor Cuitláhuac and ~40% of Tenochtitlan's population, shattering resistance.

It was a convergence of greed, faith, geopolitics, and microbial catastrophe.