Pachacuti Inca Yupanqui was the ninth Sapa Inca of the Kingdom of Cusco which he transformed into the Inca Empire. Most archaeologists now believe that the famous Inca site of Machu Picchu was built as an estate for Pachacuti.
In Quechua Pachakutiq means "reformer of the world", and Yupanki means "with honor". During his reign, Cusco grew from a hamlet into an empire that could compete with, and eventually overtake, the Chimú. He began an era of conquest that, within three generations, expanded the Inca dominion from the valley of Cusco to nearly the whole of western South America. According to chronicler Garcilaso de la Vega, Pachacuti created the Inti Raymi to celebrate the new year in the Andes of the Southern Hemisphere. Pachacuti is often linked to the origin and expansion of the Inti Sun Cult.