Huáscar initiated the war; appointed as emperor and claiming the throne, he wanted to defeat Atahualpa's competition.

Atahualpa was tactically superior to his brother in warcraft and to the mighty armies of Cuzco, which their father had stationed in the north part of the empire during the military campaign.

The new infectious disease erupted in epidemics and caused high mortality and disaster for the Inca and other indigenous peoples, who had no immunity.

Since the auguries were negative, the great priest (Villaq Umu) returned to Tumebamba for Huayna Capac to make a new choice.

As in some other cultures, the Inca violated incest rules to keep religious and political authority limited among a small elite.

[6] According to the French historian Henri Favre the panaka of Topa Inca was in the Hurin (low) part of Cusco.

To announce his loyalty, Atahualpa sent his most trusted captains to Cuzco, along with generous gifts of gold and silver (as was customary).

Just before the Spaniards arrived in Cajamarca, Atahualpa sent troops to Cusco to capture Huáscar, and headed south himself to execute him.

[18] Generals Chalcuchimac, Quizquiz, and Rumiñawi are believed to have been born in the northern part of the empire, and transferred their loyalty to Atahualpa.

People loyal to Atahualpa created a new capital in Quito, so they could follow their preferred ruler and gain favor within the government.

According to chronicler Diego de Rosales, at the moment of the civil war an Inca army was suppressing a rebellion in the Diaguita lands of Copiapó and Coquimbo.

[19] With the rebellion brutally repressed and the Inca giving rebels "great chastise", the commander of the army departed north to support Huáscar, a cousin.

[20] The local Cañari supported the attack, in order to expel the nearest source of power, with the aim to oust the Inca.

"[24] Following this victory, Atahualpa strengthened his army and continued south into his brother's land, winning every encounter.

He first tried peaceful means to gain loyalty from Huáscar's men; when that did not work, he killed large numbers of opponents.

[25] When he finally arrived in Cajamarca, Atahualpa sent the majority of his army ahead, led by his head generals, while he stayed in the safety of the city and explored rumors that the Spaniards were entering the land.

The battle starting on the hillside of Vilcas seemed to favor Huáscar stationed in a stone fortress at the top of the hill, but eventually he retreated.

Conflicts between conquistadors and rebellions End of the Neo-Inca state Atahualpa was saluted as a hero; he recaptured Cajamarca, making camp outside the city with some 40,000 troops[27] while Chalcuchimac and Quizquiz chased Huáscar's army to the south.

[31] While holding Atahualpa in custody, Pizarro told him he would have Huáscar brought to Cajamarca and would determine which brother was the better Sapa Inca.