“Die Religion in Geschichte und Gegenwart” (RGG) (Religion in Past and Present ), and its first edition in particular, achieved a significant position in the history of theology like no other encyclopaedia. On the one hand, it lent expression to the dominant theological trends of its time, while on the other it provided theological impulses of its own.This study recreates the importance of the RGG for the history and politics of theology in the context of the publishing history of Protestant lexicography. Lexico-political issues are discussed with regard to aspects of academic, theological, educational and publishing policies.The study closes a gap in the research, as theological encyclopaedias have hitherto been seen as a neglected field of research.