Question: What year did the film, which starred the actress who was best known as the estranged wife of Rudolph Valentino, first release?

Context paragraphs:
Rudolph Valentino: Rodolfo Alfonso Raffaello Pierre Filibert Guglielmi di Valentina d'Antonguella (May 6, 1895 – August 23, 1926), professionally known as Rudolph Valentino, was an Italian naturalized American actor who starred in several well-known silent films including "The Four Horsemen of the Apocalypse," "The Sheik," "Blood and Sand," "The Eagle," and "The Son of the Sheik."  He was an early pop icon, a sex symbol of the 1920s, who was known as the "Latin lover" or simply as "Valentino".  His death at 31 caused mass hysteria among his female fans and further propelled him to iconic status.

Jean Acker: Jean Acker (October 23, 1893 – August 16, 1978) was an American film actress with a career dating from the silent film era through the 1950s.  She was perhaps best known as the estranged wife of silent film star Rudolph Valentino.

When Love Grows Cold: When Love Grows Cold is a lost 1926 silent film drama directed by Harry O. Hoyt, and starring Clive Brook and Natacha Rambova in her only screen starring performance.  Rambova was chiefly famous for being the wife of Rudolph Valentino.  The film was originally titled "Do Clothes Make the Woman?"  But in view of Valentino's recent divorce from Rambova, the distributor took the opportunity to bill her as 'Mrs Valentino' and changed the title to "When Love Grows Cold".  She was mortally offended and never worked in film again.

Anthony Dexter: Anthony John "Tony" Dexter (January 19, 1913 – March 27, 2001) was an American actor known for his striking resemblance to silent film hero Rudolph Valentino, whom he portrayed in the 1951 biographic "Valentino".  Dexter sometimes used the pseudonym Walter Craig.  He was known for portraying many real-life characters such as Captain John Smith, Captain William Kidd, Billy the Kid and Christopher Columbus.

Beyond the Rocks: Beyond the Rocks is a 1906 novel by Elinor Glyn.  The novel was later adapted into a 1922 silent film in which Gloria Swanson and Rudolph Valentino (credited as Rodolph Valentino) starred together for the only time.  The film was directed by Sam Wood and distributed by Paramount Pictures.

Rudolph Valentino filmography: Rudolph Valentino (1895–1926) was an Italian-born actor in the era of silent films.  He emigrated to the United States in 1913 and took a string of temporary menial jobs before becoming a film extra in 1914.  He appeared in several films until 1921—many of which are now lost.  That year he got his major break when he appeared in the role of Julio in "The Four Horsemen of the Apocalypse".  According to Valentino's biographer, Noel Botham, the film was "hailed ... [as] a masterpiece and Valentino as a star"; the film grossed $4.5 million at the North American box office.

A Rogue's Romance: A Rogue's Romance was a 1919 American silent crime drama film produced and released by the Vitagraph Company of America.  It was directed by James Young and starred matinee star Earle Williams.  Rudolph Valentino (billed as Rudolph Volantino), who was then a young unknown dancer, also makes an appearance in a bit part as an Apache dancer.  The film is now considered lost.

A Society Sensation: A Society Sensation is a 1918 American silent comedy-drama film starring Carmel Myers and Rudolph Valentino (credited as Rudolpho De Valentina), directed by Paul Powell and released by Universal Pictures under the name Bluebird Photoplays.  When it was re-released in 1924, it was cut down to 24 minutes to include only Valentino's scenes, although it was Carmel Myers who originally starred in the film.

Camille (1921 film): Camille is a 1921 American silent drama film starring Alla Nazimova as Marguerite and Rudolph Valentino as her lover, Armand.  It is based on the play adaptation "La Dame aux Camélias" ("The Lady of the Camellias") by Alexandre Dumas, "fils", which was first published in French as a novel in 1848 and as a play in 1852.  "Camille" is one of numerous screen adaptations of Dumas, "fils"' story.  The film was set in 1920s Paris, whereas the original version took place in Paris in the 1840s.  It had lavish Art Deco sets and Rudolph Valentino later married the film's art director, Natacha Rambova.

The Ladder of Lies: The Ladder of Lies is a lost 1920 American drama silent film directed by Tom Forman and written by Edith M. Kennedy and Harold Vickers.  The film stars Ethel Clayton, Clyde Fillmore, Jean Acker, Irving Cummings, Charles Meredith and Ruth Ashby.  The film was released on July 11, 1920, by Paramount Pictures.

Supporting paragraphs: The Ladder of Lies Jean Acker
Answer: 1920