The Inca ruler captured by Spanish forces at the Battle of Cajamarca was Atahualpa.
The clash took place on November 16, 1532, when Francisco Pizarro’s small Spanish force ambushed Atahualpa’s retinue in Cajamarca’s main plaza. Atahualpa had recently emerged victorious from a civil war against his half-brother Huáscar and was the dominant ruler of the Inca realm.
The Spaniards used cavalry, steel weapons, firearms, and surprise against a largely unarmed ceremonial procession. Thousands of Atahualpa’s attendants were killed, while the ruler himself was seized and held hostage. His capture gave Pizarro enormous leverage over the Inca state.
A common mix-up is Huáscar, who was Atahualpa’s rival and half-brother—not the ruler captured at Cajamarca. Atahualpa later offered a vast ransom of gold and silver, but the Spanish ultimately executed him in 1533.