Mank, filmmaker David Fincher’s new film that’s now streaming on Netflix, is a lovely movie – especially for cinephiles. But it is also a very dense movie, packed with allusions and nods to figures operating in and around 1930s Hollywood. The film – which was scripted by Fincher’s father Jack Fincher – ostensibly tells the story of how Herman J. Mankiewicz (Gary Oldman) wrote the initial screenplay for Citizen Kane, and the film operates in two separate time periods. Flashbacks reveal moments from Mankiewicz’s time in 1930s Hollywood that would inspire the characters and story of Citizen Kane, while the frame story aspect of the film finds Mankiewicz laid up with a broken leg, working day and night to deliver a first draft of the script for the young wunderkind Orson Welles (Tom Burke).

But Mank is a film that doesn’t really stop to explain situations or historical figures. It works quite well without them, but if you’re not incredibly familiar with how Hollywood operated in the 30s or the central figures that served as inspiration for Citizen Kane, you may find yourself a little bit lost as the movie whizzes by.

You absolutely have the option of going in blind, but if you want a brief primer before you watch Mank so as to better familiarize yourself with its cadre of characters, we’ve put together a historical “who’s who” along with what you need to know about each person going in.

Herman J. Mankiewicz – Played by Gary Oldman

The central figure of Mank is screenwriter Herman J. Mankiewicz, who is played in the film by Gary Oldman. The movie’s story covers moments from Mank’s life from 1930 up through early 1940, and it’s important to know that in 1930 Mank was one of the highest-paid Hollywood screenwriters in the world. He helped usher in the age of “talkies” working as a screenwriter and uncredited script doctor on a number of films, especially comedies. Mank was known for his wit, both on the page and in real-life.

Indeed, Mank was a heavy drinker and you’ll see in the film he’s frequently in some state of disarray. But his charisma made him a favorite of William Randolph Hearst, who frequently invited Mank to his dinner parties for his company. Hearst would often invite Mank to come stay at his massive estate San Simeon, which inspired Charles Foster Kane’s similarly massive (and empty) compound in Citizen Kane.

Mank’s brother Joseph L. Mankiewicz (Tom Pelphrey) also appears in Mank, as Joe was also a successful writer and producer in Hollywood as well – a more straight-laced younger brother to his flamboyant kin.

William Randolph Hearst – Played by Charles Dance

The main inspiration for Charles Foster Kane was William Randolph Hearst, played in Mank by Charles Dance. He was a massively successful American businessman and newspaper publisher who also won two elections to Congress, yet failed to win his elections for Mayor of New York City and later Governor of New York State. While he initially ran as a progressive, he became a staunch conservative sometime in the 1930s, frequently wielding his many newspapers as a weapon to influence the politics of the day. Hearst also gained a negative reputation for interviewing Adolf Hitler in 1934 and running columns by Nazis.

In his personal life, Hearst carried on a decades-long affair with film actress Marion Davies (played in the film by Amanda Seyfried) despite being married to someone else. He also gained a reputation for micromanaging Davies on film sets, which contributed to her reputational decline.

The biggest wedge covered in Mank is when Hearst insisted on Davies being cast as historical figures in MGM movies, only for Davies to be passed over for the lead roles (namely MGM’s Marie Antoinette). This led to Davies exiting MGM in favor of Warner Bros.

Marion Davies – Played by Amanda Seyfried

First a chorus girl, actress Marion Davies garnered a career in motion pictures after being spotted by William Randolph Hearst on the stage. He financed her first films himself and helped promote her career through his newspapers, but she found success all the same thanks to her knack for comedic roles in silent films. Davies struggled with the transition to talkies, however, and retired from movies in 1937.

Davies served as the thinly veiled inspiration for the character of Susan in Citizen Kane, Charles Foster Kane’s mistress for whom he sinks money and resources into building up a career. But while Kane paints an unflattering portrayal of Susan as somewhat talentless, Mank offers up a more nuanced portrayal of Marion Davies – someone smarter than she looks with a keen awareness of how she's perceived by others. She struck up a close friendship with Mank, which is covered elegantly in Fincher’s film.

Louis B. Mayer – Played by Arliss Howard

Louis B. Mayer is a larger-than-life figure who loomed over old Hollywood as co-founder of Metro-Goldwyn-Mayer studios, and who served as inspiration for the character of Mr. Bernstein in Citizen Kane. During the time period in which Mank takes place, MGM was one of the biggest studios around – but Hollywood was also suffering the effects of the Great Depression. Mayer was a conservative and backed Frank Merriam in the 1934 gubernatorial election in California against Upton Sinclair (played by Bill Nye in Mank). Yes, this election for Governor of California plays a role in the story of Mank.

Irving Thalberg – Played by Ferdinand Kingsley

Hot-shot producer Irving Thalberg (Ferdinand Kingsley) made a significant mark on Hollywood at a young age and helped create MGM alongside Louis B. Mayer. He was immensely successful, helping shepherd productions like Ben-Hur and Mutnity on the Bounty, and as head of production at MGM interacted directly with Mank and Davies during the time in which Mank is set.

Orson Welles – Played by Tom Burke

You may be surprised to learn that Mank isn’t so much about the making of Citizen Kane as it is about the inspiration for it, and to that end Kane co-writer/director/producer/star Orson Welles only plays a small role in Fincher’s film. But it is an integral one. At the time that Welles approached Mank about writing Citizen Kane, the two had been collaborating on scripts for the radio show The Campbell Playhouse. They brainstormed ideas for Kane before eventually settling upon William Randolph Hearst as a target, and Welles was in high-demand after his 1938 radio adaptation of The War of the Worlds. The young filmmaker essentially had carte blanche for his next project, and he and Mank opted to go big.

Watch Citizen Kane

The best prep you can do is to watch Citizen Kane before you see Mank, and my colleague Matt Goldberg wrote a whole essay on why.