A pre-Inca coastal polity centered on the pilgrimage/oracle site of Pachacamac, formed in the Lurín and Rímac valleys south of Lima after the Wari Empire's collapse; famed irrigation engineering supported a wealthy desert-valley society and a religious center that outlasted the Inca conquest as an imperial shrine.
Absorbed into the Inca Empire around 1469-1470 and reorganized as the Inca province (wamani) of Pachacamac, though the oracle/shrine retained religious prestige under Inca rule.
Modern archaeological monograph on Pachacamac specifically during the Late Intermediate Period, i.e. the Ichma/Ychsma polity's floruit before Inca conquest.
Spanish-language study focused specifically on the Pachacamac lordship (Ichma polity), its organization and religious role.