Pachacuti Inca Yupanqui was also known Pachacutec. Pachacuti was the one who transformed a small Inca kingdom into the famous empire, Tawantinsuyu. He was the was the ninth Emperor (1438-71 ). Once he became Inca he started to win surrounding area. He followed a good technique. He sent his people to the neighboring area with the message , surrender and be part of Inca empire. Those who did not obey the message he went for a battle and and captured the new areas. Afterwards his kingdom was expanded and became the most powerful Empire in South America. He was the fourth Emperor of the Hanan dynasty.
According to many chroniclers, After Viracocha left the Cusco while being attacking by Chancas, Pachacitu Cusi Yupanqui defended the city and defeated the enemy. After that he declared himself as Inca.