Since Inca didn't invent writing, there is no definite record how they started. Once Spaniard conquered the land, they started to write on the history on Inca. But it was difficult to write on event passed 200 years. So there is always doubt on the actual beginning of Inca. Inca legends says Manco Capac and his siblings were sent up to the earth by the sun god. It is also known that they emerged from the cave of Pacaritambo.
Manco Capac ruled the Cuzco for about forty years. He established some codes of laws during his regime. After Manco Capac died next Inca emperors continued to flourished. Though kingdom was not much expanded until the reign of Inca Pachacuti.
Incan people started to form their big Monarchy under the leadership of Pachacuti. In 1438 under the command of Great Pachacuti Inca began their greatest expansion. During is period , he along with his son Tupac Inca brought a vast area of South America; under the control of Inca Empire.
When Pachacuti became emperor Cusco was only a city where Inca lived. But Pachacuti reorganized the kingdom of Cuzco into an empire. He converted his empire ship to a new governmental system which was known as Tahuantinsuyu. In this system there was a federal government and four provincial government. Head of the federal system was Inca. And head of the other provincial government was Inca nobles. Pachacuti is also known to be the creator of Machu Picchu. Though it is not still clear whether it was used as his home or as a any other purpose.
Since Manco Capac founded this dynasty, it was ever-growing, but it got its greatest acceleration during great Pachacuti. Pachacuti had a special way of expanding the empire keeping peace in the region. He collected information with his spies on some region on strength and organization and of the people of that locality. Then he sent his messengers with valuable gifts to those regions asking them to join Inca empire. At this stage most of the ruler agree to join, to avoid defeat. Then they sent their top persons to Inca and learnt Inca administration and the land eventually become a part of Inca Empire.
Under Empire Pachacuti people of Cusco finally created a vast political Empire which united and controlled the extensive territory from northern Ecuador to Chile - an empire with a population of three to seven millions and an area covering 380,000 square miles.
After Pachacuti his son Tupac Inca Yupanqui continued the mission. Even when Pachacuti was alive and remained Emperor, Tupac expanded vast land towards north being the head of the army. Tupac started in 1463 and continued after Pachacuti's death. Tupac's greatest win was against Chimor kingdom, one of the strongest nation during those days.
Tupac Inca's son Huayna Capac also added significant lands to the south. When Incas reached at their peak, the Empire included Peru and Bolivia, some part of Ecuador, a large part of Chile. The empire also extended up to Argentina and Colombia.
