The working titles of the film were Madame Walewska and Marie Walewska. An onscreen prologue reads: "This is a story of an historic love, the imaginative detail supplied by the dramatist has not violated the spirit of this immortal romance." According to a feature article in Stage in Oct 1937, the film cost in excess of $2,000,000, and Monterey, CA was used as a location subsitute for the island of Elba and Napoleon's retreat from Moscow was filmed partially at the Los Angeles Ice and Cold Storage Company. The article also notes that Greta Garbo first brought the Wacla Gasiorowski book to the attention of M-G-M executive producer Irving Thalberg in 1934. A news item in HR in Nov 1935, noted that M-G-M had just bought the rights to the book, and its English language dramatization by Helen Jerome, as a vehicle for Garbo and Charles Boyer. A 9 Feb 1937 HR news item noted that Robert E. Sherwood, Zoë Akins and David Boehm had been engaged to work on the script for the film in addition to two of the writers credited onscreen, Salka Viertel and S. N. Behrman. Early HR production charts include Akins and Talbot Jennings as additional writers on the film. The extent of Sherwood's, Boehm's, Akins' and Jennings' contributions to the released film has not been determined. A HR production chart includes Shepperd Strudwick in the cast, however, he was not in the viewed print and is not mentioned in other contemporary sources. A modern source notes that Czech director Gustav Machaty worked as a fill-in director during Clarence Brown's brief illness, which may have been Machaty's first work in the as a director in the United States. His first credited film was Within the Law in 1939 (see below).
       According to information in the Howard Dietz Collection at the AMPAS Library, Conquest cost $2,732,000 to produce and grossed $2,141,000, resulting in a net loss for M-G-M of $1,397,000. Comparison of these figures with budgets and grosses of other M-G-M films indicates that the film lost more money than any other picture made by the studio from the 1920s through the 1940s.
       Var review notes that Alexandre Walewska, the son of Marie and Napoleon was a diplomat of some distinction during the mid-nineteenth century and achieved more fame than either of the former emperor's other two sons. It also notes that by historical record Marie and Alexandre were among the few faithful followers who stayed with Napoleon until the end. A 1966 Polish film entitled Marie Walewska was based on the same source as the 1937 M-G-M version.