Caligula (Italian: Caligola) is a 1979 Italian-American erotic historical drama film focusing on the rise and fall of the Roman Emperor Caligula. It stars Malcolm McDowell, Teresa Ann Savoy, Helen Mirren, Peter O'Toole and John Gielgud. It is the only feature film produced by the men's magazine Penthouse. Producer Bob Guccione, the magazine's founder, intended to produce an explicit pornographic film with a feature film narrative and high production values. He intended to cast Penthouse Pets as extras in unsimulated sex scenes filmed during post-production by Guccione and Giancarlo Lui.
Guccione hired screenwriter Gore Vidal to draft the film's script and Tinto Brass to direct the film. Brass extensively altered Vidal's original screenplay, leading Vidal to disavow the film. The final screenplay focuses on the idea that "absolute power corrupts absolutely". Brass and Guccione disagreed over Guccione's use of unsimulated sexual content, which Brass refused to film. Because the producers did not allow Brass to edit the film, they changed its tone and style significantly without consulting the director and added hardcore sex scenes not filmed by Brass; he also disavowed the film.
The film's release was controversial; it was met with legal issues and controversies over its violent and sexual content. Although reviews were overwhelmingly negative (though McDowell's performance as the title character was praised), Caligula is considered to be a cult classic and its political content was considered to have significant merit.