Well, Quentin Tarantino is certainly having no problems filling out the cast list for his latest flick, Once Upon a Time in Hollywood. In fact, it seems like half of Hollywood has joined in the past week. Then again, he did start filling out the project's IMDb page by announcing that he had pulled off the casting coup of the decade by getting both Leonardo DiCaprio and Brad Pitt to agree to co-star, and from there it seems the director has had his choice of talent. Dakota Fanning, James Marsden, and Al Pacino are just some of the boldface names who have signed on.

Tarantino's ninth film will be the director's first that won't be produced by Harvey Weinstein. It also comes after frequent Tarantino muse Uma Thurman revealed an onset injury she endured on the set of Kill Bill that she felt Tarantino didn't handle correctly. (To be fair, Thurman herself said she'd work with Tarantino again on the right project.) Still, neither fact is proving to provide any bad juju around the project. At least in Hollywood.

The film will take place in Los Angeles during the particularly notorious summer of 1969 and blend fictional characters with real-life events. DiCaprio will play Rick Dalton, a washed-up former star from a TV western. Pitt plays his former stunt double Cliff Booth. Their glory days are both behind them, and they're struggling to find new relevance in Hollywood. As it happens, Dalton happens to live right next door to Sharon Tate, the actress who was murdered by followers of Charles Manson. That is, more or less, a quick summary of what we know, though these recent cast announcements give us more insight.

Here, an update of all the actors who have joined the film, the characters they're playing, and what it could all mean for the still somewhat mysterious project.

Actors Playing a Real-Life Character

Margot Robbie as Sharon Tate

At 26 years old, Tate was quickly mounting the peaks of Hollywood. Her breakthrough role two-years prior in Valley of the Dolls nabbed her a Golden Globe nomination. She married director Roman Polanski in 1968, and was eight-and-a-half months pregnant when she and her house guests were murdered by members of the Manson family. Nabbing Robbie for the part, fresh off her first Oscar nomination and in the midst of her success as Harley Quinn, seems to indicate that the character will have a major role in the film.

Dakota Fanning as Squeaky Fromme

Lynette Alice "Squeaky" Fromme was a prominent member of the Manson Family, but interestingly she wasn't there on the night of the Tate murders. However, she did camp outside the courthouse during the trial. Eventually she'd wind up in jail herself for attempting to assassinate President Gerald Ford in 1975.

Damian Lewis as Steve McQueen

"The King of Cool" was expectedly invited to Tate's house the night of the murders, but instead he ran into a woman and decided to cheat on his wife instead. His near brush with death, however, did shake McQueen and left him much more paranoid than before. He would also give the eulogy at Jay Sebring's funeral.

Emile Hirsch as Jay Sebring

At the time of his murder at 35, Sebring was not only one of Hollywood's top celebrity hairdressers but also Tate's former lover. Tate broke up with him to start her relationship with Polanski, and Polanski was not only cool with the two remaining friends but befriended Sebring himself.

Burt Reynolds as George Spahn

Spahn was a nearly blind 80-year-old rancher who became notorious after it was discovered he let the Manson Family stay on his ranch. Manson instructed his young female followers to have sex with Spahn as part of the deal.

Nicholas Hammond as Sam Wanamaker

Sam Wanamaker is very much a real person but has no direct or obvious connection to the Manson murder or even the summer of 1969 in Los Angeles. He was an American director and actor who feared his liberal leanings would have him blacklisted from Hollywood at the height of the red scare. So, while he was working in England he decided to stay there permanently and restart his career.

Actors Playing Fictional a Character

Leonardo DiCaprio as Rick Dalton

As mentioned, the faded Western star.

Brad Pitt as Cliff Booth

His stunt double.

Al Pacino as Marvin Shwarz

Dalton's agent.

Clifton Collins Jr. as Ernesto The Mexican Vaquero

It's unclear who the character is, but this is not one of Tarantino's finest name choices. If the actor isn't ringing a bell, you most recently know him best as Lawrence/El Lazo on Westworld. Judging from the casting of Marsden as well, it seems like Tarantino is a fan of the show.

Keith Jefferson as Land Pirate Keith

No clue here, but while Jefferson is far from a household name he appears to be a Tarantino favorite. He was also in The Hateful Eight and Django Unchained.

Actors Playing...We're Not Sure Actually

Luke Perry as Scott Lancer

There is no real-life Scott Lancer, but incidentally back in the summer of 1969 there was a television character named Scott Lancer. He was one of the main characters of the short-lived Western series Lancer. As you'll recall, DiCaprio is playing a former star of a TV Western, so this doesn't seem incidental. However, this could be something of an easter egg–like nod to the show, or maybe, in some way, Perry is playing the character? He does bare something of a resemblance to the character's portrayer, Wayne Maunder.

Actors Who Have Been Cast but Have No Roles Clarified

The returning Tarantino favorites: Michael Madsen, Kurt Russell, Tim Roth, and Zoë Bell.

The Tarantino newcomers: Timothy Olyphant, James Marsden, and child actresses Julia Butters and Aundrea Smith.

Real-Life Characters Who Haven't Been Cast

Charles Manson

Is Jared Leto busy, or is it possible that Manson himself may not be in the film?

Tex Watson, Susan Atkins, Linda Kasabian, and Patricia Krenwinkel

These are the Manson Family members who actually carried out the murders. It's possible the castings are still TK, or that the murders themselves take place offscreen or are only alluded to. Who knows? Technically, the movie isn't about the murders, just a guy and his stunt double who happen to live next door.

Wojciech Frykowski and Abigail Folger

The aspiring screenwriter and the coffee heiress were also victims of the Manson slaughter.

Roman Polanski

Polanski was working in Europe on the night of the murder and hence not present, but Tarantino has indicated he does have a presence in the movie. However, he may be a particularly unthankable character to play. He's been in exile in Europe since the 1970s following his drugging and raping of a 13-year-old girl.

Related: Leonardo DiCaprio, Brad Pitt, and Quentin Tarantino's Movie: Everything We Know So Far