Pachacuti Inca Yupanqui, also called Pachacútec (Quechua: Pachakutiy Inka Yupanki,), was the ninth Sapa Inca of the Chiefdom of Cusco, which he transformed into the Inca Empire (Tawantinsuyu). Most archaeologists now believe that the famous Inca site of Machu Picchu was built as an estate for Pachacuti. In Quechua, the cosmogonical concept of pachakutiy means "the turn of the world" and yupanki could mean "honorable lord". During his reign, Cusco grew from a small town into an empire that could compete with, and eventually overtake, the Chimú empire on the northern coast.
Evidence and an uncertain chronology
Pachacuti is often considered the first historical Incan emperor, despite various mythological elements of his reign. Various historians associate Pachacuti with the rewriting of the previous Inca rulers' reigns to justify Incan imperial expansion. The nature of Pachacuti's reign, the cosmological concepts associated with it, the lack of physical representations and of archeological evidence made some scholars come to the conclusion that Pachacuti was an Incan ideological and cosmological concept. The linguists, anthropologists, archeologists, ethnologists and historians Martti Pärssinen, Catherine Julien, Rodolfo Cerrón Palomino, Alfred Métraux, Brian S. Bauer, John Howland Rowe, Franck Salomon, Waldemar Espinoza Soriano, José Antonio del Busto Duthurburu, and María Rostworowski, and Carmen Bernand consider Pachacuti to be historical, while others, such as Pierre Duviols, Juan Ossio Acuña, Reiner Tom Zuidema, Gary Urton, and Franck Garcia consider Pachacuti to be mythological or mytho-historical.
The Incas of Cusco did not systematically count years, and dates of Inca mytho-history are only approximations based on comparisons between colonial documents or archeological data. An exact date for the Chanka–Inca War, which marked the beginning of Pachacuti's reign, is not known, since it happened several generations before the arrival of Europeans, maybe in the beginning of the 15th century. However, the dates recorded by colonial chroniclers, though unrealistic, were potentially based on Inca mytho-historical knowledge put on quipu records. Inca history was transmitted through oral traditions, quipu cords, and pictographic representations, and had several versions and historiographical genres, mainly the "life history" and "genealogical" genres.
The rise of a new ruler
Pachacuti's given name was Cusi Yupanqui, or Ripac, and he originated from the female lineage of Iñaca Panaka, in the moiety of Hanan Cusco ("high Cusco"), in complementary opposition to the moiety of Hurin Cusco ("low Cusco"). According to the accounts of the Spanish chroniclers, he was the son of the eighth ruler of Cusco, Inca Viracocha, whose lineage (panaka), however, was Sucsu Panaka. Analyzing the colonial writings, the historian and anthropologist María Rostworowski concluded that, based on Andean traditions of succession, which allowed for the "most able" to take power, Pachacuti was not the son of Inca Viracocha, rendering him illegitimate in the eyes of the Spaniards, who believed in European concepts of primogeniture.
In the early 15th century, the Cusco confederation, stretching 40 kilometers around the city of Cusco, faced an invasion by the Chankas, the Incas' traditional tribal archenemies. Multiple versions of the encounter exist, the most accepted one being supported by the majority of reliable Spanish sources. The ruler, Inca Viracocha, and his co-ruler Urco, fled the scene, while Cusi Yupanqui rallied the army, accompanied by four of Viracocha's generals, and prepared the defense of the city. During the subsequent assault on Cusco, the Chankas were repelled so severely that legend tells even the stones rose up to fight on Yupanqui's side. At the battle of Yahuar Pampa, the Inka army won a decisive victory over the Chankas and asserted its dominance.
Expansion and reform
Local kurakas (lords) were integrated using the principle of reciprocity and the "attachment system", where the Inca emperor held personal relations with allied local chiefs and "gifts", in the form of feasts, women, or materials, were exchanged in return for submission, reduced sovereignty, alliance and the construction of hatuncancha (administrative centers). Pachacuti occasionally elevated individuals from the class of yanakunas, servants who weren't obligated or entitled to the obligations and rights of reciprocal exchange, to rulers of local chiefdoms who had rebelled or refused Inca domination. His first military campaign, led personally by the emperor and his general Apo Mayta, was set against the Chankas' former allies, and the chiefdoms surrounding Cusco.
In Andean cosmology and mythology, Pachacuti is an important figure along with the creator deity Viracocha and the mythical first Inca Manco Cápac. Pachacuti's role was that of an archetype of the perfect Inca ruler according to the philosophical principles of the Inca ruling caste, and of spreading the Inca cultural model and pantheon to the various ethnic groups of the Andes. Pachacuti built irrigation networks, cultivated terraces, roads and hospices. The "Road of the Inca" (Qhapaq Ñan) stretched from Quito to Chile. Pachacuti is also credited with having displaced hundreds of thousands in massive programs of relocation and resettling them to colonize the most remote edges of his empire.