1532
Battle of Cajamarca
The setting
Cajamarca, northern Peru
Enclosed town plaza surrounded by buildings (ambush ground)
Reveal the outcome
Recorded sideSpanish conquistadors
Recorded resultdecisive victory
Spanish ambushed Atahualpa's lightly armed retinue, killing thousands and capturing the emperor in minutes
How the atlas explains it
Pizarro lured Atahualpa into a confined plaza, then unleashed cavalry, gunfire, and steel against an unarmed ceremonial retinue. Surprise, the panic caused by horses and firearms (unknown to the Inca), and the immediate seizure of the emperor collapsed resistance. Disease (smallpox) had already swept the Andes ahead of the Spanish, killing the prior emperor and triggering the civil war that left the realm divided (disputed in extent).
What followed
Decapitated the Inca state in a single stroke and opened the conquest of Peru.