His novel Der Patriot was turned into a play and filmed in 1928, directed by Ernst Lubitsch.
The Nazi party seized all his property due to his Jewish heritage.
[1] The French film La Tragédie impériale (1938), was based on his novel.
His work as a screenwriter included None Shall Escape (1944), Conflict (1945), and The Return of Monte Cristo (1946).
Neumann produced the first successful stage adaptation of War and Peace in 1942.