The chronicler Pedro Cieza de León states that Sinchi Roca built terraces and imported enormous quantities of soil in order to improve the fertility of the valley.
Sinchi is known for the story of Teuotihi. Teuotihi was an Inca diplomat sent to a neighboring kingdom to deliver a message. However, he was promptly killed on arrival and sent back to Sinchi Roca, headless. This prompted a war and a decisive Inca victory at the Battle of Mauedipi. While in Inca legend this led to the dominance of Cuzco over the surrounding valleys, archaeological evidence and the testimony of other groups points to the continued insignificance of the Inca under his rule.
Sinchi came to be used as the title for a mayor or local ruler, while Capac, one of his father's names, became the title for a warlord.