It can be said that those who know he works of Karl Friedrich Schinkel (1781-1841), Ludwig Persius (1803-1845) and Friedrich August Stuler (1800-1865) in Berlin and Potsdam also know the architects' work as a whole in each case. The truly gigantic lifework of Schinkel extends from Aachen to St. Petersburg; Berlin and Potsdam have about a third of his work. During his short life Persius worked almost exclusively in Potsdam and its intimate vicinity; he was the King's architect. Stuler's work is found in a region extending from Cologne on the Rhine to Masuria, with some important buildings in Stockholm and Budapest as well. About a quarter of his work can be found in Potsdam and Berlin where Stuler too was the King's architect.
Until his retirement Hillert Ibbeken was a professor of geology at the Freie Universitat Berlin, but his lifelong occupation has been architectural photography. Barry Bergdoll studied at Columbia University in New York and at Kings College of Cambridge University, England. He is professor of architectural history at Columbia University and the Philip Johnson Chief Curator of Architecture and Design at the Museum of Modern Art in New York. His special interest is in the architecture of France and Germany since the middle of the 18th century.