Using a custom-designed database of 388,000 first editions of German Literature this paper investigates the long-term development of genre-indicating subtitles over more than 500 years of literary history. This approach adds a social-institutional perspective to recent work in the field of genre theory, and is a first step towards combining historical testimony, i.e. historical actors’ classifications, and textual features in a single model. Starting from the fundamental question of how many books have generic subtitles, the paper analyses the use of the most common genre labels, the relation between generic subtitles and genre production, periods of the permanent presence of generic terms (institutional cycles) and periods of generic differentiation. It identifies recurrent patterns in the development of generic subtitles using K-Means-Clustering and Dynamic Time Warping (DTW) and sheds light on literature’s changing relation to history and truth, thereby underpinning recent theoretical work on the practices of poetic invention.