This thesis explores how Egypt’s militant extremists used theological sources and the methodology of Islamic juridical-religious thought as instruments of legitimization for acts of political violence. Most studies dealing with the topic of Muslim extremism in Egypt are defined by a dominant interpretive paradigm, which treats Muslim extremists as political reactionaries, responding to a variety of political, economic, social, and cultural grievances. Although such grievances certainly played an important role in the development of extremism, the theological dimension of extremist ideologies has been drastically understudied. This thesis puts forth two correlative arguments. First, this thesis argues that the phenomenon of Muslim extremism in Egypt cannot be fully understood, without understanding its theological dimension. Secondly, this thesis argues that the historical trajectory of extremism and militant theological thought in Egypt from 1954-1997 unfolded in three distinct and heterogeneous phases, each with its own unique characteristics.