This introduction sets out the aims and approach of the book. Following an introduction to the Norwegian post-war reckoning and a review of the existing literature on the topic, it argues that only an analysis of the full time span of the trials can uncover their complex dynamics and the changing positions of their key actors over time. The introduction then sets out the analytical framework of the book, which is to explore the – at times competing – legal and political rationales of the trials in face of a rapidly changing political and social climate.