Most of the existing khipu are from the Inka period, approx 1400 – 1532 CE. The Inka empire stretched from Ecuador through central Chile, with its heart in Cuzco, a city in the high Andes of southern Peru. Colonial documents indicate that khipu were used for record keeping and sending messages by runner throughout the empire. There are approximately 600 khipu surviving in museums and private collections around the world.
Photo Courtesy of Peabody Museum, Harvard University
The word khipu comes from the Quechua word for “knot" and denotes both singular and plural. Khipu are textile artifacts composed of cords of cotton or occasionally camelid fiber. The cords are arranged such that there is one main cord, called a primary cord, from which many pendant cords hang. There may be additional cords attached to a pendant cord; these are termed subsidiaries. Some khipu have up to 10 or 12 levels of subsidiaries. Khipu are often displayed with the primary cord stretched horizontally, so that the pendants appear to form a curtain of parallel cords, or with the primary cord in a curve, so that the pendants radiate out from their points of attachment. When khipu were in use, they were transported and stored with the primary cord rolled into a spiral. In this configuration khipu have been compared to string mops.
Each khipu cord may have one or many knots. Leland Locke (see references) was the first to show that the knots had numerical significance. The Inkas used a decimal system of counting. Numbers of varying magnitude could be indicated by knot type and the position of the knot on its cord. Beginning in the 1970’s, Marcia and Robert Ascher conducted invaluable research into the numeric significance of khipu, and developed a system of recording khipu details which is still in wide use today among khipu researchers. More recently, researchers such as Gary Urton have recognized the depth of information contained in non-numeric, structural elements of khipu.