After his immense success with the first two Godfather films, Francis Ford Coppola took over directing Apocalypse Now from his friend George Lucas, who was intending to make it as a black-and-white cinema verite art film before landing the deal for A New Hope.
Coppola intended to shoot Apocalypse Now over four months, though things went wrong from the get-go, and the film's nightmarish production lasted longer than a year. Shooting in the jungles of the Philippines, the crew experienced serious problems with weather, and had to deal with the challenges of hauling equipment through a remote jungle. The production issues were so intense, they became the subject of a documentary, Heart of Darkness.
Martin Sheen was brought to the set a few weeks after filming began, after Coppola fired Harvey Keitel, who was originally cast as the lead. The project required an internalized actor in the lead and, according to Coppola's Apocalypse Now Blu-ray commentary, Keitel was not the right man for the job. When Sheen arrived, he found a chaotic set filled with sick crew members.
John Milius's original script was being deconstructed and rebuilt every day by Coppola, who had no idea what the ending would be. Sheen had a heart attack during production, and Coppola suffered an epileptic seizure. Desperate to save the film, Coppola shoveled millions of dollars of his personal money in order to finish production.
Then there was Marlon Brando. A legend at that point, Brando showed up severely overweight, a look not favorable for a man playing a Green Beret. Brando infamously refused to learn his lines and resorted to improvising. His scenes were shot in darkness in order to hide how large Brando had become. Adding to difficulties was Brando’s refusal to work with Dennis Hopper. As a result, scenes involving Hopper and Brando had to be completed with the actors shooting lines separately.
Other problems included difficulties with the Philippines government and a production designer who obtained actual cadavers to use as set decoration. Ultimately, Coppola’s Apocalypse Now was released to immense critical acclaim and is now regarded by many to be one of the greatest war films ever made.