Pachacuti

Timeline

1. 1438–1450Cusco · Cusco BasinAround 1438 Cusco was invaded by the powerful Chanka confederation; the reigning Inca Viracocha fled the city, while Prince Cusi Yupanqui (the later Pachacuti) stayed to resist and miraculously routed the invaders. After his triumph he deposed his father, proclaimed himself Sapa Inca, and took the name Pachacuti ('shaker of the earth' in Quechua). He immediately reformed: reorganizing the army, establishing the elite orejones warriors, promoting Quechua as the empire's lingua franca, and beginning to rebuild Cusco in a grid pattern shaped like a puma. This period laid the organizational foundation for later large-scale expansion.
2. 1451–1460Cusco; Machu Picchu; Lake Titicaca · Inca EmpireBetween 1451 and the 1460s Pachacuti combined military expansion with grand construction, reaching the most brilliant phase of his rule. Militarily, he ordered his son Tupac Inca Yupanqui to conquer the peoples of Chinchaysuyu to the north, while personally or through generals conquering the Collasuyu peoples around Lake Titicaca to the south, incorporating the Aymara and heirs of the Tiwanaku culture. In construction, around the 1450s he oversaw building the mountain royal estate of Machu Picchu, showcasing the mastery of Inca ashlar masonry, while greatly expanding the Qorikancha Sun Temple in Cusco, covering its walls with gold leaf to make it the empire's holiest religious center. Administratively, he systematized the use of quipu as an empire-wide information-recording tool and perfected the chasqui relay network, bringing distant provinces under efficient control.
3. 1460–1471Cusco · Inca EmpireIn his later years Pachacuti gradually transferred military command to his son Tupac Inca Yupanqui, devoting himself to religious rites and institutional construction. He systematically compiled Inca mythology and cosmology, strengthening the worship of Inti as the core of imperial ideology, and established astronomical ritual systems such as the Intihuatana ('hitching post of the sun'). He died around 1471; his body was mummified as a mallqui according to Inca tradition and placed in the royal mummy hall of Cusco, receiving regular sacrifices from later descendants. During his reign Tawantinsuyu expanded from the Cusco Basin to millions of square kilometers, becoming the largest empire of pre-Columbian America, and his military, administrative, and architectural legacy profoundly influenced subsequent Inca rulers.