Founded in 1880, the Munich art gallery Julius Böhler was one of the largest art dealers in the German-speaking world in the first half of the 20th century, with an international reputation. For many years, the history of the gallery has been one of the most urgent desiderata of provenance research. In 2015, the Zentralinstitut für Kunstgeschichte was able to acquire the object index system, the photo folders, and the customer index of the art gallery Julius Böhler with the support of the Deutsche Forschungsgemeinschaft (DFG). With funds from the Ernst von Siemens Kunststiftung, the object index system and the customer index were digitized, initial research was initiated, and thus a basis for answering incoming inquiries was created. Since 2019, the index system has been recorded in a database with funding from the Deutsches Zentrum Kulturgutverluste. In the process, the most important information about the artworks traded and the actors involved in the transactions will be transcribed. In addition, persons, institutions, auctions and locations are - as far as possible - standardized according to common standards. The collected, processed and enriched data will - according to the legal framework - be put online. A first beta version has been available since June 1, 2021.