Quentin Tarantino's Once Upon a Time in Hollywood is a fictional film, but the tale of late-1960s L.A. includes many real-life figures. Among them are actress Sharon Tate, played by Margot Robbie, and cult leader Charles Manson, who orchestrated the 1969 murders of Tate and eight others. However, that story isn’t at the heart of the movie, which largely focuses on stars Leonardo DiCaprio and Brad Pitt, who play a fictional down-and-out Western actor and his stuntman best friend. And when the film does tackle the Manson murders, Tarantino makes major changes to the real-life story.