Francisco Pizarro, Hernando's older brother, received chief rights of discovery and conquest in Peru, or New Castile, and the Governorship of the territory from King Charles I of Spain in the Capitulation of July 1529.

[9] Hernando Pizarro assumed control of Cusco after returning from Spain and hoping to improve relations with Manco, for both personal and Spanish interests, released the Inca leader from confinement in January 1536.

[10] Manco Inca left Cusco on April 18, 1536 after securing Hernando Pizarro's approval to conduct religious ceremonial activities in the Yucay Valley and return with gold.

[11] Hernando, realizing the grave mistake, sent his brother Juan Pizarro and seventy cavalrymen from Cusco on a mission to disperse the Incas gathered in the nearby Yucay Valley.

Additionally, the steep elevation encountered while approaching the fortress inhibited the use of cavalry, effectively neutralizing one of the Spaniards' primary tactical advantages and potential options for counter-assault.

[16] The Inca warriors barraged the city with slings projecting hot stones wrapped in cotton and incendiary arrows that ignited thatched roofs and quickly spread fire throughout Cusco.

The Incas recognized the significant battlefield effectives of horses, so the native warriors planted elevated peltasts, around the city, that launched ayllos to entangle and disable the cavalrymen.

[20] Realizing the direness of the situation, after about a week of being pinned down, the Spanish decided their survival depended on recapturing the walled complex of Sacsayhuamán which served as the main base of operations for the Inca army.

[23] The capture of Sacsayhuamán eased the pressure on the Spanish garrison at Cusco; the fighting now turned into a series of daily skirmishes interrupted only by the Inca religious tradition of halting attacks during the new moon.

[24] During this period, the Spaniards successfully implemented terror tactics to demoralize the Inca army, which included an order to kill any woman caught and cutting off the hands of captured men.

It is suggested by some that by this action he threw away his only real chance to expel the Spaniards from the lands of the Inca Empire, but it was probably the only realistic choice he had considering the arrival of Spanish reinforcements from Chile led by Diego de Almagro.