The concept of diversity eludes a clear and universally viable definition. It is both a theoretical construct – vividly debated in social sciences and humanities – and a universal catchphrase used by various actors to bundle, control and mediate certain dynamics shaped by categories such as origin, religion, gender or class. The contributions in this Festschrift for Reinhard Johler trace this ambiguity in different disciplinary perspectives, spaces and time periods and address different aspects of diversity both as a field of study and a heuristic concept. They investigate how “diversity” can be employed for (historical) ethnographical research on social life.