Quipu ( KEE-poo), also spelled khipu (Ayacucho Quechua: kipu,; Cusco Quechua: khipu,), are record-keeping devices fashioned from knotted cords. They were historically used by various cultures in the central Andes of South America, most prominently by the Inca Empire. A quipu usually consists of cotton or camelid fiber cords, and contains categorized information based on dimensions like color, order, and number. The Inca, in particular, used knots tied in a decimal positional system to store numbers and other values in quipu cords.
Numbers in knots
Quipus held information, decipherable by officials called quipucamayocs (Cusco Quechua: khipu kamayuq, lit. 'khipu specialist',), classified in various categories, narrated from the most important to the least important category, according to color, number, and order. To date, most of the information recorded on the quipus studied by researchers consists of numbers in a decimal system, such as "Indian chiefs ascertain which province had lost more than another and balanc the losses between them" after the Spanish invasion. In the early years of the Spanish conquest of Peru, Spanish officials often relied on the quipus to settle disputes over local tribute payments or goods production. The quipucamayocs could be summoned to court, where their bookkeeping was recognised as valid documentation of past payments.
While Spanish colonial chroniclers, such as Inca Garcilaso de la Vega, hinted at the numerical system of quipus, it is Leslie Leland Locke who is often credited with first demonstrating that many quipus encode numbers using a base-10 positional notation. Starting in the late 1960's and building on Locke's foundational work, Marcia Ascher and Robert Ascher analyzed several hundred quipus, revealing that most of the information recorded by quipu knots is numerical and can be systematically interpreted. Most quipus use three main types of knots: simple overhand knots; "long knots", consisting of an overhand knot with one or more additional turns; and figure-eight knots. The Aschers also identified a fourth, and less common, type of knot—a figure-eight knot with an extra twist—which they refer to as an "EE" knot.
Information beyond counting
Some have argued that far more than numeric information is present and that quipus are a writing system. This would be an especially important discovery as there is no surviving written record of the Inca Empire predating the Spanish invasion. Making deciphering more complex, the Inca 'kept separate "khipu" for each province, on which a pendant string recorded the number of people belonging to each category.' How exactly non-numeric information is encoded is disputed, though scholars are working to collect and analysis khipu data beyond just their knot values, exploring other variables—such as cord twist, color, fiber, attachment orientation, and knot variations—as signifiers of non-numerical data.
Historians Edward Hyams and George Ordish claim, for example, that quipus were recording devices, similar to musical notation, in that the notes on the page present basic information, and the performer would then bring those details to life. A 2005 report in the journal Science, titled "Khipu Accounting in Ancient Peru", may represent the first identification of a quipu element for a non-numeric concept. The report details a sequence of three figure-eight knots at the start of a quipu that seems to be a unique signifier. It could be a toponym for the city of Puruchuco (near Lima), or the name of the quipu keeper who made it, or its subject matter, or even a time designator.
Administrators and colonial encounters
Quipucamayocs (Quechua khipu kamayuq, "khipu-authority"), the accountants of Tawantin Suyu, created and deciphered the quipu knots. Quipucamayocs could carry out basic arithmetic operations, such as addition, subtraction, multiplication, and division. They kept track of mita, a form of taxation. The quipucamayocs also tracked the type of labor being performed, maintained a record of economic output, and ran a census that counted everyone from infants to "old blind men over 80". The system was also used to keep track of the calendar.
According to Guaman Poma, quipucamayocs could "read" the quipus with their eyes closed. Quipucamayocs were from a class of people, "males, fifty to sixty", and were not the only members of Inca society to use quipus. In 1532, the Spanish Empire's conquest of the Andean region began, with several Spanish conquerors making note of the existence of quipus in their written records about the invasion.
The earliest known example comes from Hernando Pizarro, the brother of the Spanish military leader Francisco Pizarro, who recorded an encounter that he and his men had in 1533 as they traveled along the royal road from the highlands to the central coast. It was during this journey that they encountered several quipu keepers, later relating that these keepers "untied some of the knots which they had in the deposits section, and they tied them in another section."