Apache was based on Paul I. Wellman's novel Broncho Apache, which in turn was inspired by a true story. Burt Lancaster plays Massai, a lieutenant of the great Apache warrior Geronimo (here depicted as an old man, played by Monte Blue). Though his tribe has signed surrender terms with the conquering whites, Massai refuses to do so. He escapes from a prison train and conducts a one-man war against the white intruders-and against some of his own people. Along the way, he claims Nalinle (Jean Peters), whom he previously regarded as a traitor to his cause, as his wife. John McIntire plays famed Indian scout Al Sieber, who-in this film, if not in real life-is sympathetic to the Indians' plight and Massai's single-purposed cause. The real-life counterpart to Massai was killed by Sieber's minions after agreeing to call off the hostilies; United Artists objected to this, forcing producer/star Burt Lancaster to shoot an unconvincingly happy ending.
~ Hal Erickson, All Movie Guide