This thesis is a source study in the Islamic heresiographical tradition. Although it focuses exclusively on the Kharijite sects, it aims to construct an analytical framework against which other heresiographical material might be measured. The study consists of two parts. Part One is devoted to the Ash$\sp{\rm c}$ariite-Mu$\sp{\rm c}$tazilite works which have become standard among modern scholars. It is argued that these works (dating mostly from the fourth Islamic century and later) preserve material which circulated in Iraq during the first three centuries. An attempt is made to isolate and chart the patterns of transmission within the extant portion of the tradition in order to explain the way the tradition was originally assembled.

Part Two focuses on a body of literature not widely known among Islamicists: the Hanafite-Maturidite heresiographical tradition of eastern Iran and Transoxania. The existence of this alternative to the standard Ash$\sp{\rm c}$arite-Mu$\sp{\rm c}$tazilite tradition has not generally been recognized by scholars. The one or two sources previously mentioned in the scholarship have been treated independently, without reference to their membership in a wider literary tradition. The most important task of Part Two, then, is proving the existence of a distinct literary tradition more or less independent of the standard works.

After the characteristic features of the eastern tradition are described, the material contained in the texts is analyzed. It is suggested that the Kharijite sects served in these works as a foil for the Hanafite-Maturite doctrine of faith (iman). It is further argued that the material preserved in the eastern sources can at times get us behind the standard accounts, particularly as far as the later Persian Kharijite sects go.