This chapter explores the implications of adjudicators’ identity and diversity for the normative and sociological legitimacy of international courts and tribunals. It considers a range of elements that constitute a person’s identity, including gender, national origin, legal culture, religion, and ethnicity. In doing so, the chapter provides an overview of the volume’s contribution to the existing literature on matters of identity and diversity, focusing among other on appointment processes, judicial decision-making and adjudicators’ legacies. The chapter outlines the various justifications used to advocate greater diversity, highlights the relevance of institutional frameworks, and engages with the question whether the pursuit of diversity risks affecting quality. It analyses existing and emerging regulation as well as practices relating to diversity, in search of the reasons for its lack on international benches. Finally, it outlines the tripartite structure underlying the volume (the importance of an adjudicator’s identity before, during, and after their time on the bench), explains how the individual chapters fit into this framework and sets out how future scholarship may build on the present research findings.