Salonwagen of Otto von Bismarck (1872) — this wagon was a (lobbying) gift to the “Blood and Steel” Reichskanzler (chancellor) Otto von Bismarck. He mostly used it for private travel from Berlin to his property near Hamburg — the wagon would simply attach to a regular fast train (but of course scheduled an extra stop wherever Bismarck wanted to get off).
On display in the DB Museum (German Railways) in Nuremberg (Nürnberg), Germany.