The term radicalisation is being used by politicians, activist groups, the media, governmental organisations, and many other groups, although it lacks conceptual clarity and insufficient consideration is given to its historical context. This edited book offers a reflective overview of the state of the research by addressing questions such as 'what is radicalisation?' and 'does the concept help us to understand political violence differently?' across the social sciences. From a global selection of scholars, it explores the definition and the utilisation of the concept of radicalisation, pathway modelling, and the impact of gender, religion, and ideologies on radicalisation. It combines theoretical and historical analysis, providing a good introduction for any scholar and student starting in that field.