Who were the mythical founders of the Inca Empire?

According to a legend compiled by the mestizo chronicler Inca Garcilaso de la Vega (1539 - 1616), in his work "The royal comments of the Incas", published in Lisbon in 1609, Manco Cápac and his sister-wife Mama Ocllo were sent by their father Inti, the Sun god, to found the Inca Empire.

The siblings emerged from the depths of Lake Titicaca (in Peru and Bolivia) and marched north. They carried a golden rod, given by the Sun god. Wherever the golden rod sank, there they would found a city. They walked until they reached the Acamama Valley and climbed to the highest point of the valley, Huanacaure Hill, and that is the place where the golden rod sank.

The city they founded was named Cusco (in Peru today) and it eventually became the capital of the Inca Empire.