This dissertation reports on the nature of social differentiation in the prehispanic Huaracane population of the Moquegua Valley, Perú. Prior to this research, the topic of Huaracane social organization had received little attention, although evidence from mortuary contexts suggested the development of social inequalities and wealth accumulation later in the Huaracane sequence. In order to develop a better understanding of Huaracane social organization, systematic surface collections and large-scale horizontal excavations were undertaken at the potential chiefly center of Yahuay Alta. The results of this investigation revealed the site to be multicomponent: inhabited during two distinct phases. The first occupation took place during the 2^nd century AD and possibly extended into the 3^rd century AD, towards the later end of the previously known Huaracane sequence. The second occupation continued into the 8^th century AD, during the Middle Horizon Period, proving that the Huaracane population continued in the Moquegua region long after the establishment of the well-known imperial Wari and Tiwanaku colonies. The study of inter-household variability in status and wealth during these two phases of occupation indicated: (1) no domestic parallels with the wealth accumulation and exotic materials found in burial treatments; (2) only limited household wealth/status differences during the early occupation of this settlement, represented by differential consumption of chert and fineware serving vessels; and (3) that serving/feasting activities increased in scale and shifted from domestic to public contexts during the later occupation of this settlement. The research revealed a subsistence pattern based on resources other than maize, and that although this Huaracane community was in close proximity to many Wari and Tiwanaku colonial settlements, it maintained traditional material patterns, adapting no stylistically Wari or Tiwanaku material culture.