The Incas emerged as a distinct group near present-day Cuzco in approximately 1200 CE. Although their expansion did not begin until 1438 under Pachacuti Inca, by the time the Spanish arrived about 1532 their empire, known as Tawantinsuyu, or the Land of the Four Quarters, extended from Northern Ecuador to Central Chile, a distance of some 3,500 kilometers.

The Incas emerged from conflicts between a number of competing polities in southern Peru and Bolivia. Military success, particularly against the Chanca, helped the Incas to believe that they were under the protection of the sun god, Inti, of whom the emperor was an earthly manifestation. As such, the Incas considered they were on a divine mission to bring civilization to those they conquered. Their expansion was also driven by the development of the royal mummy cult, according to which the lands owned by a dead emperor were needed to support his cult, thereby forcing the new...