Same with the Aztecs of Tenochtitlan, who kept meticulous bureaucratic records. We know quite a bit about them thanks to the friars who got to see a lot of the

Same with the Aztecs of Tenochtitlan, who kept meticulous bureaucratic records. We know quite a bit about them thanks to the friars who got to see a lot of the records while Cortes' expedition were guests (/captors) of Montezuma. They all burned during the final battle for Tenochtitlan.