In 1531, the Spanish conquistador Francisco Pizarro arrived in Peru with his Spanish army. After three exploratory missions, he established the settlement of San Miguel de Piura. In 1532, he sent Hernando de Soto to continue exploring the land and to make contact with the Inca ruler, Atahaulpa. De Soto sent messengers to Atahaulpa requesting a meeting with him and Atahaulpa agreed willingly. They met on November 15th, 1532.
Although de Soto claimed that the Spanish had come in peace in the name of Charles V of the Holy Roman Empire and of Spain, Atahaulpa remained suspicious. Apparently, he had heard reports that some Spanish soldiers had desecrated one of the temples to one of the Inca gods. Atahaulpa demanded an explanation and an explanation from Pizarro himself. He agreed to meet with Pizarro the next day, however.
Before Atahaulpa arrived the next day with thousands of mostly unarmed soldiers and attendants, Pizarro put his men in position around the city of Cajamarca. When Atahaulpa arrived, Pizarro's priest, Friar Vinvente de Valverde attempted to explain the Catholic religion to Atahaulpa and his servants. He even demanded that Atahaulpa accept Catholicism as the new religion of the Incas and Charles V as their new emperor. Atahaulpa refused, and the Spanish unleashed a surprise attack against the Inacs. They immediatly captured Atahaulpa himself and killed all of his commanders. This left the rest of the army confused and organized.
Although the Incas greatly outnumbered the Spanish, the Spanish won because of they had the element of surprise. The fact that the Incas had never seen horses before and were scarred of them also helped as did the technological advantage that the Spanish. Whereas the Incas were armed only with clubs and leather armor, the Spanish soldiers had steel swords, army, helmets, guns, and maybe even canons.
The Inca were unable to recover from this defeat because they had a highly centralized chain of command. With all of their military leaders dead and their kidnapped, the remaining Inca were left leaderless. It took the Spanish several years to fully consolidate their control over the Inca territory, but Atahaulpa made it easier. By holding him, the Spanish could always threaten to kill him if they felt threatened by any of his followers.
Thus, the Spanish conquered the Inca empire not only with military might and technological advantage, but with guile and a disregard for the conventional rules of warfare. The Spanish kept Atahaulpa as "insurance" until he looked like a liability. On July 26, 1533, the Spanish convicted him of twelve crimes and executed him.
