Inca Civil War

The Inca Civil War, sometimes called the War of the Two Brothers, was a struggle for the throne of the Inca Empire fought from about 1529 to 1532 between the half-brothers Huáscar and Atahualpa. Atahualpa won, but his victory came just as Spanish invaders arrived, and the damage done by the war is widely seen as one reason the empire fell so quickly to them.

The emperor Huayna Capac died around 1527 at Tumebamba, in the north of the empire, probably of an epidemic disease such as smallpox or malaria that had spread ahead of the Europeans exploring the Pacific coast. His first chosen heir, Ninan Cuyochi, died at almost the same time. The Incas had no fixed rule of succession, and two of Huayna Capac's sons by different mothers came forward.

Huáscar, whose mother belonged to a leading royal lineage, was crowned in the capital, Cusco, with the backing of its nobility and high priests. Atahualpa, whose mother's origins are disputed by the sources, had spent years on campaign with his father in the north and enjoyed the loyalty of the veteran northern army and its generals, among them Quizquiz, Chalcuchimac and Rumiñawi. Some historians see the war as a contest between rival royal kin groups as much as between the brothers themselves.

Accounts differ in detail. According to the main narrative, Atahualpa sent envoys with gifts to Cusco to declare his loyalty, but Huáscar distrusted him, had some of the messengers killed and sent the others back humiliated. War followed. Huáscar's forces struck north at Tumebamba, where the local Cañari people sided with him, and Atahualpa was briefly taken prisoner before escaping and rallying his army at Quito.

From 1531 Atahualpa's generals drove south, defeating Huáscar's army near Ambato and then winning a long series of battles through the Andes towards Cusco. The campaign was brutal. Chroniclers report that the Cañari were massacred for supporting Huáscar. Estimates of the number of dead in the war vary enormously, from tens of thousands to over a million, and the true figure is unknown.

In 1532, close to Cusco, Huáscar's last army was outmanoeuvred and destroyed at Quipaipan. Huáscar was captured, and Quizquiz occupied the capital and killed many of Huáscar's supporters there.

Atahualpa was waiting at Cajamarca, in the northern highlands, when Francisco Pizarro and a small Spanish force reached the town on 16 November 1532. Atahualpa was seized in the encounter that followed. While a prisoner, and fearing that Huáscar might ally with the Spaniards, he ordered his brother killed. Pizarro collected a huge ransom of gold and silver, but in 1533 the Spaniards executed Atahualpa at Cajamarca.

The war left the empire divided, its armies weakened and its leadership in turmoil just as the Spanish conquest began. Together with epidemics and the conquest itself, it contributed to a catastrophic fall in the population of the Andes, estimated at around 95 per cent over the following century. The empire's population before these disasters is put at between six and fourteen million.

Our 1500 and 1530 maps show the Inca Empire stretching along the Andes from present-day Ecuador to Chile, the territory the brothers fought over.