Portrait Name Political Party Term of Office President of the Preußische Landesversammlung Robert Leinert Social Democratic Party of Germany 1919–1921 Presidents of the Landtag of Prussia Robert Leinert Social Democratic Party of Germany 1921–1924 Friedrich Bartels Social Democratic Party of Germany 1924–1928 1928–1931 Ernst Wittmaack Social Democratic Party of Germany 1931–1932 Hanns Kerrl National Socialist German Workers' Party 1932–1933 1933