Pachacuti

Pachacuti Inca Yupanqui (or Pachacutec; , whose name means "He who remakes the world" was the ninth Sapa Inca (1438-1471/1472) of the Kingdom of Cuzco, which he transformed into an empire, Tawantinsuyu. He began the era of conquest that, within three generations, expanded the Inca dominion from the valley of Cuzco to nearly the whole of civilized South America. He was the fourth of the Hanan dynasty, and his wife's name is given as Mama Anawarkhi or Coya Anahurque. Their son was Tupac Inca Yupanqui. 
Pachacuti reorganized the new empire, the "Tahuantinsuyu" or "the united four provinces." Under his system, there were four "apos" that each controlled one of four provinces ("suyu"). 
Despite Pachacuti's political and military talents, he did not improve upon the system of choosing the next Inca. His son became the next Inca without any known dispute, but in future generations the next Inca had to gain control of the empire by winning enough support from the apos, priesthood, and military to either win a civil war or intimidate anyone else from trying to get control of the empire. 
Machu Picchu is believed to date to the time of Pachacuti.