Focused on winning his civil war, Atahualpa fatally misjudged the Spanish. He saw the small group as a potential asset—a source of mercenaries, horses, and superior swords to be captured and repurposed. He never considered them an existential threat to his empire, which sealed his fate.

Manco first viewed the small Spanish force as mercenaries he could leverage to restore order and his own authority after the devastating Inca civil war, completely underestimating their ultimate colonial ambitions and disruptive potential.

While the Trojan Horse is legendary, its underlying strategy was commonplace. Most ancient cities fell not to brute force, which was too costly, but to treachery from within or stealthy infiltration. The horse represents the ultimate, most dramatic execution of this standard military doctrine.

The Aztecs' and Incas' centralized, hierarchical structure was their greatest vulnerability. By capturing a single leader—the emperor—the Spanish could destabilize or control the entire system. In contrast, dispersed peoples like the Maya required a long, grinding war of attrition to subdue.

The Aztec military doctrine and status system prioritized capturing enemies alive for ritual sacrifice. This cultural imperative repeatedly led them to try to seize Cortés and other Spaniards rather than kill them on the spot, providing crucial moments for the conquistadors to be rescued and escape certain death.

Openness is a tool for dominance, not just a moral virtue. The Romans became powerful by being strategically tolerant, quickly abandoning their own methods when they found better ones elsewhere. This allowed them to constantly upgrade their military, technology, and knowledge from conquered peoples.

After executing Inca emperor Atahualpa, the Spanish installed his brother as a puppet ruler. This co-opted the existing power structure, making the conquest seem like a restoration of the natural order to local chiefs and smoothing the transition of power.

The Spanish conquest of the Incas succeeded largely because they inserted themselves into an existing civil war. By siding with the southern Inca faction against the northern one, they gained crucial local allies, transforming the conflict from a foreign invasion into a complex, multi-sided war they could manipulate.

Francisco Pizarro's invasion of Peru was heavily influenced by the recent success of his cousin, Hernán Cortés, in Mexico. The fall of the Aztecs provided a tangible model for conquest, proving that small bands of conquistadors could topple vast empires. This precedent made it easier for Pizarro to secure funding and royal support.