See Mank's Cast Compared to All Their Real-Life Counterparts

Before heading to Hollywood as a screenwriter, Herman Mankiewicz started his career as a drama critic at The New York Times and The New Yorker. He found success writing on Dinner at Eight and The Wizard of Oz, but he's perhaps best known for his contributions to Citizen Kane, which is often considered one of the best movies ever made. Around 1940, Orson Welles, who was much younger than Mankiewicz, set out to collaborate with the seasoned writer on Citizen Kane — there's been controversy, however, over how much each man contributed to the script.

Often (and perhaps unfairly) compared to Susan Alexander Kane in Citizen Kane, Marion Davies was a well-known socialite and actress. Throughout her career, Davies appeared on Broadway and in films such as Runaway Romany and Cecilia of the Pink Roses. She was newspaper tycoon William Randolph Hearst's companion and mistress for over 30 years.

Joseph Mankiewicz was Herman Mankiewicz's younger brother as well as a great filmmaker in his own right. He famously penned and directed A Letter to Three Wives (1949) and All About Eve (1950) — for these projects, he earned four Academy Awards as well as other accolades in a two-year period.

In 1924, Louis B. Mayer co-founded Metro-Goldwyn-Mayer studios, cementing his reputation as a star-maker in the '20s and '30s. A powerful motion-picture executive in Hollywood, he has been likened to Harvey Weinstein due to his alleged abuse against actresses such as Judy Garland.

The son of a wealthy family, William Randolph Hearst was an infamous publisher who used his father's mining fortune to own and operate the San Francisco Examiner, filling pages with sensationalistic articles. After his success at the Examiner, he acquired more newspapers and began building his media empire. He is widely believed to be the inspiration for Charles Foster Kane in Citizen Kane — the parallels are so similar that Hearst tried to squash print reviews in Hearst publications and have Welles blacklisted from studios.

Orson Welles famously panicked Americans with his dramatic rendition of H.G. Wells' The War of the Worlds on the radio, making people believe that there really was a Martian invasion. A prolific filmmaker, he not only co-wrote and directed Citizen Kane, but also starred in it as well. A few of his other classic works include The Stranger (1946) and Touch of Evil (1958).

Producer Irving Thalberg had a reputation in Hollywood as a boy wonder for not only his youth, but also his ability to pick out just the right scripts. He oversaw hundreds of movies and streamlined the process of mass producing motion pictures. (He also produced the newsreels that helped defeat Democratic candidate Upton Sinclair, who is portrayed by Bill Nye in the film.) When he suddenly passed away of pneumonia in 1936 at the age of 37, thousands came to his funeral to mourn him.

John Houseman was an actor and producer known for his collaborations with Orson Welles, with whom he founded the Mercury Theatre company. When Herman Mankiewicz was recovering from a car accident, Houseman visited him and helped him further develop the story for Citizen Kane.