Since 2009, SLUB has been carrying out systematic provenance research projects with the support of various funding agencies. It all started with a review of the books acquired between 1945 and 1990, focussing on finding the so-called palace salvage items, which came into the possession of various cultural institutions during the expropriation of manors and palaces in the SBZ/GDR. This was followed by a project that was dedicated to the books acquired between 1933 and 1945 and to the search for Nazi loot. On the basis of the feature documentation of the palace salvage project, the books that came in after 1945 were reviewed in 2017/18 in search of the so-called secondary loot.