Stanley Baker challenged Robert Mitchum to a drinking contest. Mitchum won, allegedly after the two men had drunk non-stop for 74 hours.
Director Robert Aldrich was very dismissive of his own film in later years, once referring to it as "a terrible film, a joke"; he said there had not been enough time to develop the screenplay properly, although he also pointed out that, at least, his screenwriter, A.I. Bezzerides, was a man of Greek ancestry who knew the country and its history and traditions, whereas Leon Uris, the author of the original novel, had never even been there.
Alan Ladd was considered to play the war correspondent, but Robert Mitchum said the producers decided Ladd was too small.
The original running time was 119 minutes before it was edited down to 105 minutes for US release. The European version ran longer. In 2004 the British Film Institute screened a print with a running time of 114 minutes. Director Robert Aldrich felt that certain scenes lost their meaning with the trims made.
Robert Aldrich said in later years that he found Robert Mitchum a very good actor and that he liked him; but that feeling, it seems, was not shared. Mitchum did not appreciate Aldrich. He did not like the kind of film he was playing with, and he did not think Aldrich was a good director. Some 15 years after this film, Mitchum would only agree to act in The Yakuza (1974) if Aldrich was replaced as director - and he was.