German dictator Adolf Hitler was kept informed in detail about the extermination of the Jews, according to the German translation of a book written for the Soviet leader Josef Stalin in 1949. "The Hitler Book" makes it clear that SS leader Heinrich Himmler conferred with Hitler about the details of the mass murder, according to the historian Matthias Uhl of the Institute for Contemporary History in Berlin. “The most remarkable thing about the book is the direct connection between Hitler and the Holocaust”, Uhl said. “This is the first information showing that Hitler got real information from Himmler on the gas chambers, and that Himmler showed him the sketches of the project of the gas chambers. This is the first time that we have this information that Hitler was so involved in the Holocaust.” Not all historians agree that the book offers an important contribution. “I think it’s completely insignificant how much Hitler knew of the details of the genocide,” Wolfgang Benz, director of the Berlin Center for Research on Anti-Semitism, said. “It is clear that Hitler knew. And whether he knew about the methods in detail, or if he just told Himmler to get rid of the Jews, it’s all the same.”