THE most numerous Southern Indian peoples, west of the Maya, are today the Zapotec and Mixtec, who occupy Guerrero, Puebla, Oaxaca, and Tehuantepec. Oaxaca proper is divided into the western highland, or Mixteca, and the eastern valleys, where Zapotec is spoken. The archaeological history of the region is related to the ceramic sequence1 established by Alfonso Caso for Monte Alban near Oaxaca City. The record of Formative and Classic occupancy is continuous in this immense assembly of buildings. Its courtyards and tombs (Figure 21) spread over the contours and shoulders of the isolated mountain at the T-shaped meeting of three valleys, which converge at Oaxaca City from the north, the east, and the south. Monte Alban I and II correspond to the earliest monumental art of the region, which resembles Olmec sculpture. A vaguely defined transition (III), and Monte Alban Ilia compose the Classic era, commonly called Zapotec. Monte Alban IIIb, IV, and V spread from about the seventh century A.D. to the Spanish Conquest. They correspond to Mixtec and later Aztec domination at Monte Alban.
Mitla (Figure 23) arose during the earlier centuries of Mixtec civilization from about A.D. 700 until 900. (Note 19 and p. 91). The art of the later centuries, after 900, is characterized by metal objects, polychrome pottery, and painted manuscripts. For the Mixtec era, our main source of knowledge is the group of pictorial genealogies (Plates 52-5), recording about eight hundred years of dynastic history from the seventh century until after the Spanish Conquest.2 The Mixteca Alta, in western Oaxaca, was the highland seat of these warrior aristocracies, who overran the sedentary and theocratic society of the Classic age, much as the Toltecs later overran the post-Classic civilizations of Yucatán and Teotihuacán. Various lines of evidence confirm the age of the Mixtec tribal dynasties, but their exact historical relationships, both to the theocratic rulers of Monte Alban and to the Toltec lineages in the north, are still obscure.
Mitla was built when Mixtec society separated from a parent culture of Classic date in the eighth century, at about the time of the earliest dynastic chiefs recorded in the genealogies.3 Mixtec traits pervaded the material culture of central Mexico at the time of the Spanish Conquest. The polychrome painted ceramics and the manuscript illuminations of fifteenth-century Aztec art probably owe more to Mixtec sources than to any other tradition, so that we must review its origins in the Classic Zapotec style, recalling that Mixtec art had no separate identity until after the decay of Monte Alban, presumably in the eighth century.