Z
Costa-Gavras’ 1969 movie Z opens with a twist on the standard disclaimer: “Any similarity to real persons and events is not coincidental. It is INTENTIONAL.”
A quick search of Wikipedia turns up the story behind the film. Greek anti-war activist Grigoris Lambrakis was assassinated by two far-right extremists in 1963, as detailed in the 1967 novel of the same name by Vassilis Vassilikos. The event is apparently pretty much what is depicted in the film.
Costa-Gavras is best known here for his 1982 Academy Award-winning film Missing (starring Jack Lemmon and Sissy Spacek). Like Z and most of Costa-Gavras’ other films, it’s a political story involving the search for a missing journalist amid a coup d’état in Chile.