There's a lot that we don't know for sure about the Inca Empire, because we have conflicting accounts among Spanish colonizers, as well as the fact that Inca history itself is told non-linearly. But we do know that they used Andean accomplishments, from architecture to knotted quipu, to create a city that ruled the largest Indigenous empire in the Americas, starting with Manco Capac and the successive Sapa Inca rulers.