Battle of Cajamarca
1532 CE.
Shown on the map at -7.157°, -78.517°.
The Battle of Cajamarca, also spelled Cajamalca (though many contemporary scholars prefer to call it the Cajamarca massacre), was the ambush and seizure of the Incan ruler Atahualpa by a small Spanish force led by Francisco Pizarro, on November 16, 1532. The Spanish killed thousands of Atahualpa's counselors, commanders, and unarmed attendants in the great plaza of Cajamarca, and caused his armed host outside the town to flee. The capture of Atahualpa marked the opening stage of the conquest of the pre-Columbian civilization of Peru.
Text from the Wikipedia article Battle of Cajamarca, licensed CC BY-SA 4.0.