The Pizarro brothers' extreme degradation of Manco—urinating on him while chained—was intended to break him. Instead, it became an unforgivable act of psychological warfare that backfired, destroying any chance of a puppet regime and fueling an all-out war of resistance.

In a ruthless political move, Atahualpa directed the gold-hungry Spanish to loot two of the empire's most sacred temples. Both were located in regions loyal to his civil war rival, Huascar, effectively using the invaders as a tool to punish his internal enemies.

The small Spanish force could not have survived the siege of Cusco or conquered the empire alone. They relied critically on thousands of native auxiliaries from rival ethnic groups, as well as Inca nobles who opposed Emperor Manco, turning the conflict into a multi-sided civil war.

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.

The Spanish didn't defeat the Inca Empire at its height. They arrived after a smallpox epidemic killed the emperor and a subsequent brutal civil war between his sons shattered the empire. This left the civilization politically fractured and militarily exhausted, making it ripe for conquest by a small force.

To escape Cusco and launch his rebellion, Manco exploited his captor Hernando Pizarro's insatiable greed. He claimed he needed to leave the city to retrieve a massive golden statue of his father. Pizarro, blinded by the prospect of treasure, readily believed the lie and let him go.

The Pizarro brothers, Juan and Gonzalo, relentlessly humiliated Emperor Manco by abducting and abusing his wife and sister. This personal cruelty, driven by lust and arrogance, directly sabotaged their fragile alliance and incited the devastating siege of Cusco.

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.