The rights to Kipling's poem were bought by producer Edward Small's Reliance Pictures in 1936 in exchange for ₤4,700.
RKO took the rights as part of a production deal with Small when he moved to the company.
William Faulkner did some preliminary script work then the project was assigned to Howard Hawks.
He got Ben Hecht and Charles MacArthur to write the screenplay and the film was set to start in 1937 but was delayed to find suitable cast.
Hawks was fired from the project following the commercial failure of Bringing Up Baby and George Stevens was assigned to direct.

Originally, Grant and Fairbanks were assigned each other's role; Grant was to be the one leaving the army to marry Joan Fontaine's character, and Fairbanks the happy-go-lucky treasure hunter, since the character was identical to the legendary screen persona of Fairbanks' father.

According to Robert Osborne of Turner Classic Movies, when Grant wanted to switch parts, director George Stevens suggested they toss a coin; Grant won and Fairbanks Jr. lost his most important role.

On the other hand, according to a biography of director George Stevens by Marilyn Ann Moss entitled Giant: George Stevens, a Life on Film, the Cutter role was originally slated for comedy actor Jack Oakie until Grant requested the part because it would enable him to inject more humor into his performance, at which point Fairbanks, Jr. was brought on board to replace Grant as Ballantine.

On a more recent showing of the film on TCM, Ben Mankiewicz has contradicted the story told about the coin-flip by his colleague Osbourne, and has stated that while Grant was originally slated to play Sergeant Ballantine, and did indeed decide to switch to the more comedic role of Sergeant Cutter, he claimed that after taking over the role that may or may not have already been filled, Grant actually recommended that his former role go to his friend Douglas Fairbanks Jr. and was primarily responsible for him gaining the part.

Fairbanks Jr. claims he was cast as Cutter by Howard Hawks then asked to change.
The rights to Kipling's poem were bought by producer Edward Small's Reliance Pictures in 1936 in exchange for ₤4,700. RKO took the rights as part of a production deal with Small when he moved to the company. William Faulkner did some preliminary script work then the project was assigned to Howard Hawks. He got Ben Hecht and Charles MacArthur to write the screenplay and the film was set to start in 1937 but was delayed to find suitable cast. Hawks was fired from the project following the commercial failure of Bringing Up Baby and George Stevens was assigned to direct.
Originally, Grant and Fairbanks were assigned each other's role; Grant was to be the one leaving the army to marry Joan Fontaine's character, and Fairbanks the happy-go-lucky treasure hunter, since the character was identical to the legendary screen persona of Fairbanks' father.
According to Robert Osborne of Turner Classic Movies, when Grant wanted to switch parts, director George Stevens suggested they toss a coin; Grant won and Fairbanks Jr. lost his most important role.
On the other hand, according to a biography of director George Stevens by Marilyn Ann Moss entitled Giant: George Stevens, a Life on Film, the Cutter role was originally slated for comedy actor Jack Oakie until Grant requested the part because it would enable him to inject more humor into his performance, at which point Fairbanks, Jr. was brought on board to replace Grant as Ballantine.
On a more recent showing of the film on TCM, Ben Mankiewicz has contradicted the story told about the coin-flip by his colleague Osbourne, and has stated that while Grant was originally slated to play Sergeant Ballantine, and did indeed decide to switch to the more comedic role of Sergeant Cutter, he claimed that after taking over the role that may or may not have already been filled, Grant actually recommended that his former role go to his friend Douglas Fairbanks Jr. and was primarily responsible for him gaining the part.
Fairbanks Jr. claims he was cast as Cutter by Howard Hawks then asked to change.
Gunga Din (film)