Calpulli (from calpolli, big house), a Nahuatl term for a subdivision of an Altepetl, sometimes used synonymously with or replaced by Tlaxilacalli. There have been several definitions for calpulli, ranging from kin group to temple to the better-known territorial district (such differences arising from regional variation). There is greater agreement on the functional nature of the calpulli, often combined in groups of four, six, or eight within a single altepetl. The calpulli was the basic holder and distributor of usufruct on land to citizens, and the unit responsible for tribute collection and delivery. Each had its own leader and nobility, as well as a temple and market area. Calpulli were ranked in importance and proportionally represented in rotation at the level of altepetl administration. They were often divided into even smaller units, sometimes called calpulli or tlaxilacalli themselves. After the Spanish invasion, the calpulli persisted, retaining much of its pre-Hispanic organization.
Among the many scholars who have addressed the nature of the calpulli are Edward Calnek, "The Internal Structure of Tenochtitlán," in Ancient Mesoamerica, Selected Readings, edited by John Allen Graham (1981), pp. 337-338; Frances Berdan, The Aztecs of Central Mexico: An Imperial Society (1982), pp. 56-59; Rudolf Van Zantwijk, The Aztec Arrangement: The Social History of Pre-Spanish Mexico (1985); S. L. Cline, Colonial Culhuacán, 1580–1600: A Social History of an Aztec Town (1986); Susan Schroeder, Chimalpahin and the Kingdoms of Chalco (1991); James Lockhart, The Nahuas After the Conquest: A Social and Cultural History of the Indians of Central Mexico, Sixteenth through Eighteenth Centuries (1992), esp. pp. 16-19.