This thesis combines anthropological and Egyptological approaches in an investigation of socio-economic differentiation in Middle Kingdom Egypt. Three questions are posed: what is the extent of differentiation in this period; what are the material and spatial parameters of differentiation; and can a "middle class," often cited in the Egyptological literature, be documented within this range? These issues are especially interesting in the light of a recently advanced theory of a regimented ("prescriptive") society for the period, in which the central government sought to impose total control on the populace. Such a policy might be expected to affect the differentiation present or possible in society, through control of resources. The archaeological evidence for social differentiation was evaluated in three different mortuary contexts, based on the principle that social categories are expressed in the treatment of an individual at death. The analysis was based on a combination of archival and field research. A six month field season incorporating survey and excavation was conducted in the Northern Cemetery at Abydos, in order to gain a wide range of information on both the material remains of the burial practices of the population, and on health status (through osteological analyses). Additionally, a quantitative analysis of the published cemeteries of Haraga and Riqqa was conducted, focusing on the three variables of grave size, assemblage diversity, and wealth. The patterning of these variables in all three cemeteries indicates that at least five levels of socio-economic differentiation existed during the Middle Kingdom, with significant levels of access to labor and material resources throughout the range. This flexible and differentiated picture is borne out by archival and literary documents from the period. Within this range, a middle class might be represented by the owners of modest shaft graves and hieroglyphic monuments without bureaucratic titles. It is suggested that such a flexible system would not be possible in a rigidly controlled society; although the government probably monitored certain levels of society and economic matters, it seems likely that a flexible private system always functioned outside the government umbrella.