The part depicting Adolf Hitler in white trench coat in a the terrace having cake is taken from some extremely rare color footage taken by Eva Braun herself, Hitler's mistress and later wife, in the Berghof, Hitler's private residence in Bavaria, during his birthday. The scenes were painstakingly reconstructed not only to include postures, scenery and uniforms, but also the guests: head of SS Heinrich Himmler and Minister of Propaganda Joseph Goebbels, Eva Braun herself, Hitler's German shepherd dog Blondi and the two young boys, who were Goebbels' eldest children. There is even a part when Hitler scolds Eva from smoking and then a general looks warily to the camera when pointed at him. All of this is genuine and can be seen in the complete footage.
Rose Bosch auditioned 200 children for the role of Jo Weismann and approximately 100 for the other child roles.
A number of the characters in the film are based on real people, on whose testimonies the screenplay was based; and, as mentioned in the opening credits, every event occurring in the film, no matter how extreme, actually happened.
Producer Alain Goldman's intention was to make a French Schindler's List (1993) as he felt no French film had yet truly approached the subject.
Though widely reported as the first film to talk about the "Vel' d'Hiv Roundup", the event was actually lightly touched upon in Mr. Klein (1976), though it is true that it is the first film to make the Roundup the main subject and treat it in such detail. The roundup was also addressed in another 2010 French film called Sarah's Key.