Before entering upon the history of the Incas I wish to make known or, speaking more accurately, to answer a difficulty which may occur to those who have not been in these parts. Some may say that this history cannot be accepted as authentic being taken from the narratives of these barbarians, because, having no letters, they could not preserve such details as they give from so remote an antiquity. The answer is that, to supply the want of letters, these barbarians had a curious invention which was very good and accurate. This was that from one to the other, from fathers to sons, they handed down past events, repeating the story of them many times, just as lessons are repeated from a professor's chair, making the hearers say these historical lessons over and over again until they were fixed in the memory. Thus each one of the descendants continued to communicate the annals in the order described with a view to preserve their histories and deeds, their ancient traditions, the numbers of their tribes, towns, provinces, their days, months and years, their battles, deaths, destructions, fortresses and "Sinchis." Finally they recorded, and they still record, the most notable things which consist in their numbers (or statistics), on certain cords called quipu, which is the same as to say reasoner or accountant. On these cords they make certain knots by which, and by differences of colour, they distinguish and record each thing as by letters. It is a thing to be admired to see what details may be recorded on these cords, for which there are masters like our writing masters.
[Note 39: The system of recording by quipus is described by Garcilasso de la Vega, i. pp. 150 and 191, also ii. p. 117 and more fully at ii. pp. 121—125. Cieza de Leon mentions the quipu system in his first part (see i. p. 291 and note) and in the second part (ii. pp. 33—35, 53, 57, 61,165). At p. 32 the method of preserving the memory of former events is described very much as in the text. See also Molina, pp. 10, 169. Molina also describes the boards on which historical events were painted, p. 4. They were, he says, kept in a temple near Cuzco, called Poquen-cancha. See also Cieza de Leon (second part), p. 28.]
Besides this they had, and still have, special historians in these nations, an hereditary office descending from father to son. The collection of these annals is due to the great diligence of Pachacuti Inca Yupanqui, the ninth Inca, who sent out a general summons to all the old historians in all the provinces he had subjugated, and even to many others throughout those kingdoms. He had them in Cuzco for a long time, examining them concerning their antiquities, origin, and the most notable events in their history. These were painted on great boards, and deposited in the temple of the Sun, in a great hall. There such boards, adorned with gold, were kept as in our libraries, and learned persons were appointed, who were well versed in the art of understanding and declaring their contents. No one was allowed to enter where these boards were kept, except the Inca and the historians, without a special order of the Inca.
In this way they took care to have all their past history investigated, and to have records respecting all kinds of people, so that at this day the Indians generally know and agree respecting details and important events, though, in some things, they hold different opinions on special points. By examining the oldest and most prudent among them, in all ranks of life, who had most credit, I collected and compiled the present history, referring the sayings and declarations of one party to their antagonists of another party, for they are divided into parties, and seeking from each one a memorial of its lineage and of that of the opposing party. These memorials, which are all in my possession, were compared and corrected, and ultimately verified in public, in presence of representatives of all the parties and lineages, under oaths in presence of a judge, and with expert and very faithful interpreters also on oath, and I thus finished what is now written. Such great diligence has been observed, because a thing which is the foundation of the true completion of such a great work as the establishment of the tyranny of the cruel Incas of this land will make all the nations of the world understand the judicial and more than legitimate right that the King of Castille has to these Indies and to other lands adjacent, especially to these kingdoms of Peru. As all the histories of past events have been verified by proof, which in this case has been done so carefully and faithfully by order and owing to the industry of the most excellent Viceroy Don Francisco de Toledo, no one can doubt that everything in this volume is most sufficiently established and verified without any room being left for reply or contradiction. I have been desirous of making this digression because, in writing the history, I have heard that many entertain the doubts I have above referred to, and it seemed well to satisfy them once for all.