<P> In the last origin myth, Manco Cápac, who was the son of the sun, and his sister Mama Occlo, the daughter of the moon, were sent by the sun to look for a place to build an empire . They were to tell when they were at the right place by carrying a special rod with them at all times . Wherever the rod sank into the ground, this was where they were to create a new city . The rod sank into the ground in Cuzco . </P> <P> The knowledge of these myths is due to oral tradition since the Incas did not have writing . Manco Cápac, who became the leader of his tribe, probably did exist, despite lack of solid evidence . The archeological evidence seems to indicate that the Inca were a relatively unimportant tribe until the time of Sinchi Roca, also called Cinchi Roca, who is the first figure in Inca mythology whose existence can be supported historically . </P> <P> The Inca people began as a tribe in the Cusco area around the 12th century AD . Under the leadership of Manco Cápac, they formed the small city - state of Cusco Quechua Qosqo . </P> <P> In 1438 AD, under the command of Sapa Inca (paramount leader) Pachacuti, whose name meant "world - shaker", they began a far - reaching expansion . The land Pachacuti conquered was about the size of the Thirteen Colonies of the United States in 1776 and consisted of about half the Andes mountain range . </P>

Where is it believed that the inca tribe began