Despite a reputation for reaching for their revolvers at the merest mention of culture, the Nazis were among the most ruthless, avaricious and methodical art collectors ever to cast a greedy eye and thieving hand over other people's property.
"Use every means of transport to get all works of art out of Florence … [save] works of art from English and Americans," ran one of Heinrich Himmler's orders. "In fine get anything away that you can get hold of. Heil Hitler."
That appetite for the most beautiful and precious works of European art saw thousands of pieces stolen from their owners between 1933 and 1945 and entire collections raided, scattered and lost.
The quest to recover them and, where possible, return them to their rightful places has been under way for almost seven decades.
Now, thanks to a deal between some of the world's leading archives and museums, an online catalogue of documents has been created to help families, historians and researchers track down the missing artworks.
Under an agreement signed on Thursday by organisations including Britain's National Archives, the Commission for Looted Art in Europe, the US National Archives and Records Administration (Nara) and Germany's Bundesarchiv, the records will be available through a single web portal.
The records include files documenting the systematic expropriation of Jewish property, Adolf Hitler's plans to establish a Führermuseum crammed with looted art in his Austrian hometown of Linz and the interrogation of art dealers.
The British documents, which cover the years 1939 to 1961, also lay out the efforts made to identify the stolen works and reunite them with their owners.
Among them is a report from a British art expert and RAF intelligence officer who was dispatched to Switzerland in 1945. The paper may have faded to yellow, but Douglas Cooper's exasperation with the Swiss authorities remains fresh to this day.
"Until I arrived here five weeks ago, practically nothing had been done," he writes. "And still no steps have been taken by the Swiss government to put the looted pictures in security. This means that it is still possible for any of the present holders to dispose of them."