The 'Battle' of Cajamarca was the unexpected ambush and seizure of the Inca ruler Atahualpa by a small Spanish force led by Francisco Pizarro, on November 16, 1532. The Spanish killed thousands of Atahualpa's counsellors, 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 Inca civilization of Peru.