Who were the Chancas?
The Chanca tribe was an ethnia that had settled in the Ayacucho area. They were divided into the Hanan (upper) and Hurin (lower) sections, and claimed to have their origin or pacarina in the two lakes of Choclococha and Urcococha. They were a warlike people, and having conquered Andahuaylillas, its new objective was Cusco.
During Viracocha's government, the Chancas left Paucaray -three leagues from Parcos- and split into three armies. They were so sure of an easy conquest of Cusco that two of the armies were sent to Contisuyo and the third took the Cusco road.
On his side, the now old and tired Inca left Cusco to its fate and took refuge together with his son Urco in the fortress of Chita. In this context, a hero figure appeared to defend Cusco, the young prince Cusi Yupanqui.
Cusi Yupanqui, later to be known as Pachacutec, was born of the lineage of Iņaca Panaca. The chronicler Betanzos gives an epic narration of the clash between Cusi Yupanqui and the Chancas. Cusi had only a small group of warriors, a fact which enhanced his victory. Cusi's army built deep pits camouflaged with branches around Cusco, as traps for the Chancas.
Moreover, the "Sun Priest" and his followers constructed (and appropriately dressed) an "army" of stone soldiers standing guard and ready to go into battle, in front of the city. Cusi Yupanqui tried to make alliances with his neighbors, but they decided to await the result of the battle to take the victor's side.
Urco, the son of Viracocha, had abandoned Cusco together with his father. He had been named co-ruler, and at that time had already received the borla (tassel or fly-whisk), the symbol of power. On the very same day he received this emblem, he married his number one wife, according to Inca custom. However, this young man showed little warlike spirit and did not fight for Cusco.
Inca successions were hectic affairs, as the right of seniority in succession (primogeniture) was not recognized. Power was awarded to the "most skilful and efficient" of the candidates. This is why all Inca successions were marked by intrigues, infighting and murders. In this sense, the struggle between Huascar and Atahualpa was quite a normal occurrence, but took on continental significance due to the great expansion of the Inca Empire.
Spies reported the approach of the Chancas, having seen them rush down the hillside of Carmenca, brandishing their weapons and emitting war-whoops. They had donned red war-paint and had braided their hair in tiny pigtails for battle. In the euphoria of their onslaught they fell headlong into the pits.
A curaca called Chaņian Curi Coca of the ayllus of Choco-Cachona patiently awaited the enemy approach, and then attacked so bravely that he defeated them in his sector. Even the stone soldiers built by the priests took part in the fray.
They became the pururaucas, mysterious allies of the Incas, spreading terror among the enemy troops. To decide the outcome of the battle, Cusi Yupanqui sought out the Chanca chief Uscovilca, killed him, captured the sacred idol he carried, and by showing it to the Chancas demoralized them and precipitated their flight.
Shortly after that, the Chancas were able to regroup, but Cusi was victorious again, this time thanks to help from neighboring tribes. The Incas rushed in pursuit of their enemies and captured some valuable loot that would help them to further the expansion of their future empire.
Having defeated the Chancas, Cusi Yupanqui gathered his booty and prisoners and returned to the fortress where Viracocha and Urco were hiding.
According to the Inca custom, the sovereign had to place his foot on the spoils and the captured enemy chiefs as an act of assumption of ownership of the defeated and their lands. Viracocha refused to submit to this, and transferred power to Urco as regent in his stead.
Cusi did not agree with this decision and, after insisting on his right to a share of power, decided to return to Cusco. On the road he was waylaid by Viracocha's soldiers, but knowing the old Inca's wiles, he was prepared for the attack.
After that, he was able to return to Cusco without further problems. Cusi shortly thereafter was able to appropriate the "imperial tassel", and according to ancient custom changed his name to Pachacutec Inca Yupanqui, and as such launched the golden age of Cusco. Inca expansion can be traced to the beginnings of the fifteenth century and forms one of the modern chapters of Andean history.
The successive rulers of the Incas were well chosen and Pachacutec as founder was succeeded by his son, the empire builder Tupac Yupanqui and he in turn by Huayna Capac, the great statesman.
The oral traditions of the songs sung in the presence of former Inca's mummies during annual festivities in the great plaza of Aucaypata and the written history of the period allow us to form a less legendary picture of the Incas who ruled at around the time of the Spanish invasion.