At its height, the Inca Empire extended over 2,600 miles. The challenges of sustaining an empire with that reach, not to mention one built so fast, required extraordinary resourcefulness. The Inca Empire met these demands by adapting aspects of local culture to meet imperial needs. For instance, the empire demanded that the ayllus, the local communities with shared ancestors, include imperial tribute in the rotation of labor and the distribution of harvested foods. (See “Listening to the Past: Felipe Guaman Poma de Ayala, The First New Chronicle and Good Government.”)

As each new Inca emperor conquered new lands and built his domain, he mobilized people and resources by drawing on local systems of labor and organization. Much as ayllus had developed satellite communities called mitmaq, populated by settlers from the ayllu in order to take advantage of remote farming areas, the emperor relocated families or even whole villages over long distances to consolidate territorial control or quell unrest. What had been a community practice became a tool of imperial expansion. The emperor sent mitmaq settlers, known as mitmaquisuna, far and wide, creating diverse ethnic enclaves. The emperor also consolidated the empire by regulating marriage, using maternal lines to build kinship among conquered peoples. Inca rulers and nobles married the daughters of elite families among the peoples they conquered. Very high-ranking Inca men sometimes had many wives, but marriage among commoners was generally monogamous.

The reciprocal labor carried out within ayllus expanded into a labor tax called the mit’a (MEE-tuh), which rotated among households in an ayllu throughout the year. Tribute paid in labor provided the means for building the infrastructure of empire. Rotations of laborers carried out impressive engineering feats, allowing the vast empire to extend over the most difficult and inhospitable terrain. An excellent system of roads — averaging three feet in width, some paved and others not — facilitated the transportation of armies and the rapid communication of royal orders by runners. Like Persian and Roman roads, these great feats of Inca engineering linked an empire. The government also made an ayllu responsible for maintaining state-owned granaries, which distributed grain in times of shortage and famine and supplied assistance in natural disasters.

On these roads Inca officials, tax collectors, and accountants traveled throughout the empire, using elaborate khipus to record financial and labor obligations, the output of fields, population levels, land transfers, and other numerical records. Khipus may also have been used to record narrative history, but this is speculation, as knowledge of how to read them died out after the Spanish conquest. Only around 650 khipus are known to survive today, because colonial Spaniards destroyed them, believing khipus might contain religious messages that would encourage people to resist Spanish authority.