This article examines the deep epistemological and theological roots of the religious philosophy of jihd-Salafism and its role in the construction of the ideology of Boko Haram. To achieve this, four aspects are considered: first, the core theological doctrines of jihd-Salafism on the subject of takfr and hukm bi-ghayri m anzala Allh; second, the sacred texts and Islamic scriptures that have been adroitly exploited to support the jihd-Salafs' idealization, theological legitimization and meta-justification for divinely sanctioned jihd; third, the ideologues of jihd-Salafism, and how their readings of Islamic history and theology have provided a stamp of approval for the legitimization of jihd against the political rulers in the Muslim world; and fourth, an explanation of why the jihd-Salafs diverge from the interpretation of the quietist Salafs despite their unified common understanding about following the model of the Prophet and his companions. These four aspects serve as a matrix that helps to explain the enduring relationship between the religious philosophy of jihd-Salafism and the ideology of Boko Haram. In what follows, this article shows that the theological doctrines of jihd-Salafism and the cultural framing of the historical tradition of tajdid in northern Nigeria - specifically the distinctive trans-generational discourses, Islamic traditions and jihd legacy established by the eighteenth-century Islamic reformer Shehu Uthman Dan Fodio - have played a greater role in Boko Haram's legitimization of jihd than has hitherto been acknowledged.
