This book is based on findings from the Horizon2020 Project “Participation. Analysing and Preventing Extremism via Participation” (Grant Agreement 962547) funded by the European Commission. Its main goal is to provide an updated, well-informed and nuanced picture of the contemporary research into the factors influencing pathways of radicalization towards violent extremism in the European landscape. Different kinds of extremism are taken into consideration (far-right, far-left, separatist and religious extremism) through a mixed approach that combined a qualitative study with textual-statistical analyses. One of the most relevant outcomes of our research on current radicalization studies is that, for all types of extremisms analyzed, the process of radicalization is understood as an event that occurs at the intersection between a personal trajectory and a permissive, or enabling, environment. Cumulative extremism dynamics and new places of radicalization are also noted as further trends to be monitored.