Question: What is the first name of the father of the actor that was featured in the film Bulldog Drummond's Revenge?

Context paragraphs:
The Return of Bulldog Drummond (novel): The Return of Bulldog Drummond was the seventh Bulldog Drummond novel.  It was published in 1932 and written by H. C. McNeile under the pen name Sapper.

Bulldog Drummond's Revenge: Bulldog Drummond's Revenge is a 1937 black-and-white detective film directed by Louis King, produced by Stuart Walker, written by Edward T. Lowe Jr. and Herman C. McNeile (novel), and featuring John Barrymore.  The picture stars John Howard in his second appearance as Bulldog Drummond; Howard previously appeared as Ronald Colman's (who had made the first talkie "Bulldog Drummond") brother in "Lost Horizon".  Top-billed John Barrymore portrays his friend Colonel Nielsen.

John Barrymore: John Barrymore (born John Sidney Blyth; February 14 or 15, 1882 – May 29, 1942) was an American actor on stage, screen and radio.  A member of the Drew and Barrymore theatrical families, he initially tried to avoid the stage, and briefly attempted a career as an artist, but appeared on stage together with his father Maurice in 1900, and then his sister Ethel the following year.  He began his career in 1903 and first gained attention as a stage actor in light comedy, then high drama, culminating in productions of "Justice" (1916), "Richard III" (1920) and "Hamlet" (1922); his portrayal of Hamlet led to him being called the "greatest living American tragedian".

Bulldog Drummond's Bride: Bulldog Drummond's Bride is an American crime comedy thriller film produced in 1939.  It was the last film of Paramount Pictures' Bulldog Drummond film series.

Bulldog Drummond Escapes: Bulldog Drummond Escapes is a 1937 American film directed by James P. Hogan starring Ray Milland as Capt. Hugh "Bulldog" Drummond.  Paramount continued with the Bulldog Drummond series, producing seven more films over the next two years.  They replaced Milland with John Howard.

Bulldog Drummond Strikes Back (1934 film): Bulldog Drummond Strikes Back is a 1934 American comedy-mystery-adventure film directed by Roy Del Ruth.  The film stars Ronald Colman and Loretta Young.  It was a loose sequel to the 1929 film "Bulldog Drummond" which had also starred Colman.

Bulldog Drummond at Bay (novel): Bulldog Drummond at Bay was the ninth Bulldog Drummond novel.  It was published in 1935 and written by H. C. McNeile under the pen name Sapper.  It was filmed in 1937 and in 1947.

Knock-Out (novel): Knock-Out was the eighth Bulldog Drummond novel.  It was published in 1932 and written by H. C. McNeile under the pen name Sapper.  It was adapted into the film "Bulldog Drummond Strikes Back".

Calling Bulldog Drummond: Calling Bulldog Drummond is a 1951 British crime film directed by Victor Saville and featuring Walter Pidgeon, Margaret Leighton, Robert Beatty, David Tomlinson, and Bernard Lee.  It featured the character Bulldog Drummond created by the novelist Herman Cyril McNeile, which had seen a number of screen adaptations.  A novel tie-in was also released in 1951.  It was made by the British subsidiary of MGM at Elstree Studios.  The film's sets were designed by the art director Alfred Junge.

Bulldog Drummond (novel): Bull-dog Drummond (later Bulldog Drummond) was the first Bulldog Drummond novel.  It was published in 1920 and written by H. C. McNeile under the pen name Sapper.

Supporting paragraphs: Bulldog Drummond's Revenge John Barrymore
Answer: Maurice