The brief closing scene was shot in the newly developed three-strip Technicolor process; filmed in 1933, this was the first feature film to include such a sequence.
Made shortly after Hitler came to power in Nazi Germany, hence the depiction of Boris Karloff's character with his anti-Semite stance. Nazi Propaganda Minister Joseph Goebbels instead of banning the film had it re-edited to play up an anti-Jewish viewpoint.
Boris Karloff was irritated with Universal refusing to up his contract pay after the success of The Mummy (1932) so he decamped to England to make The Ghoul (1933). This immediately led to offers for non-Universal films, The Lost Patrol (1934) and The House of Rothschild (1934). Karloff happily accepted these roles as they upped his profile and enabled him to have a bit more leverage in his negotiations with Universal when they wanted him to star in The Black Cat (1934).
Ironically, this tale of Jewish moneylenders was produced by 20th Century Fox, the one Hollywood studio not to have a Jewish head (Darryl F. Zanuck).
George Arliss asked Warner Bros. to buy the play on which this film was based while he was under contract there in 1931. Warners bought the play but did not make the film. When Arliss left Warners, he convinced Darryl F. Zanuck to purchase the play from Warners for 20th Century Pictures, where it was eventually made.