All over the world, there is now a rising tide of radical ‘Islamist’ movements, which, especially since 9/11, have turned militant. Since then, terrorist attacks against civilian populations both in the West and within Muslim countries themselves have become almost daily occurrences. Several countries have been directly or indirectly affected by Islamist militancy. In Bangladesh, Islamist militants killed 156 people in the 1990s, and the country experienced at least 48 smallscale attacks that killed over 120 people between 2015 and 2016. The July 2016 attack at the Holey Artisan Café in Dhaka killed approximately 20 foreigners, while an abortive attack six days later killed two. These and other similar incidents confirmed the presence of external militant outfits in the country and the severity of the challenge. Based on an exhaustive review of the relevant literature and two stints of fieldwork in Bangladesh involving 71 in-depth interviews of highly credentialled individuals, this project seek to investigate not only the causes of radicalization but also how radicalization has unfolded since 2009. This thesis looks at both local and global factors that have served to provoke young Bangladeshis, many of whom are from relatively well-educated backgrounds, to become religiously belligerent and eventually to turn into terrorists. Ideology, it is argued, plays a pivotal role in the radicalization process and justifies violence. Most importantly, ideology proffers solutions to the micro and macro causes of commonly identifiable youth disaffection. This study mainly focuses on the Islamic State and Al Qaeda’s exploitation of religious beliefs and their construction of a mobilising, apocalyptic narrative that strikes a chord with the young, middle-class Muslims. Both organisations target them for recruitment. The thesis ends by proffering what is called a Pyramid Root Cause model,’ which attempts to tie all the causative variables of radicalization into a connected explanation of what has been happening in Bangladesh over the last decade.