This article is a contribution to the study of the Boko Haram insurgency in Nigeria. It aims to demonstrate that the ethnic identity issues in Nigeria can provide elements in understanding Boko Haram as a contextual phenomenon. Indeed, this terrorist group has taken advantage of a fragile social context fueled by problems related to ethnic identity, for its emergence and its development. These problems are also related to religion which is connected to ethnic identities and which is an important component in the Boko Haram crisis, within the Nigerian political context mainly expressed in the federalism and its consequences. From an analysis of the way problems related to different ethnic groups in Nigeria have been handled since colonial time, the article shows that the concept "Boko Haram" itself depends on this particular context which in its turn enlightens Boko Haram's terrorist actions.