This work explores the role of religious and political authority among the Ismailis of Gorno-Badakhshan, Tajikistan. Gorno-Badakhshan Autonomous Oblast (GBAO) is a mountainous region located in the eastern part of Tajikistan. It shares a long border with Afghanistan, China and Kirgizstan, and, in places, is only twenty miles from Pakistan. Badakhshan is inhabited by approximately 215000 people, most of whom identify themselves as being Nizari Ismaili Shia Muslims; they speak their various local Pamiri languages, whilst Tajik is the official language of education and state bureaucracy. This thesis documents the ways in which expressions of political and religious authority have evolved through time, and accommodated to different political contexts, which are summarised as representing four identifiable historical periods between 1895-2008. These periods are: the Afghan invasion, which ended in 1895; Russian imperial rule (1895-1917); Soviet power (1917-1991); and the aftermath of the Soviet period (1991-2008). This thesis suggests that, as is the case with many Muslim societies, political leadership and religious authority in Badakhshan were fused, and this was the pattern of secular and religious life in this area until the 1920s. In contrast, under Soviet rule, traditional norms ofleadership and authority in Badakhshan were supplanted by a secular nationalist yet indigenous leadership that was closely tied to central Soviet power. These changes followed a series of radical social and political upheavals. This thesis identifies traditional forms of religious authority with the network of religious functionaries at a range of levels. Equally, it discusses the functionaries of Ismaili political leaders that have evolved through the aforementioned periods. It does not juxtapose traditional authority with secular political power, but merely records the interaction, various degrees of conflict and accommodation, and competition between secular and religious worldviews. It intends to develop a structural explanation for the survival of religious and political authorities of Badakhshani Ismailis through the use of written sources and fieldwork data.