This chapter discusses the political, economic and religious factors that gave rise to Boko Haram, the most active terrorist group in Nigeria. It argues that Boko Haram’s tactics may be evolving from a locally focused insurgency to transnational terrorist activities, and that the movement poses a growing threat to neighbouring countries, particularly Mali and Niger. The Nigerian government’s failure to address socio-economic marginalisation, combined with heavy-handed counter-terrorism measures has hindered efforts to end the Islamist-led insurgency in the north. Nigeria’s experience and Boko Haram’s dramatic escalation of violence, provides lessons for other countries about the need to understand and tackle this new and evolving threat. Boko Haram embodies a growing regional security challenge that requires a coordinated regional response, including joint security initiatives and shared commitment to development and governance in vulnerable areas.