Following an account of jihad-inspired terrorist attacks carried out and foiled in Europe in recent years, in this paper we shall outline and define the task of radicalization research as a recently established aspect of terrorism prevention. A number of findings regarding radicalizing factors will be presented clustered around the categories individual vulnerability, the situation in the current country of residence, the profile of the Islamist movement and conflict-related developments in places of reference for collective identity and the contextualization of these factors in the narrative of Jihad.