In Arthur Penn’s 1958 film The Left-Handed Gun, Billy The Kid (Paul Newman) was portrayed as a neurotic, self-destructive teen rebel who behaved like James Dean with a six-gun. Penn threw in the framing device of having a journalist follow Billy through his career of crime. Little Big Man (1970) also features a journalist looking to embroider the facts, but this time the writer meets his match in the shape of the wizened, 121-year-old Jack Crabb (Dustin Hoffman hidden behind several layers of make-up). Crabb’s story, narrated in flashback in a croaky voiceover reminiscent of Grandpa Simpson, is so outrageously far-fetched that he is either?as the publicity material for the movie put it at the time?”the most neglected hero in history or a liar of insane proportion”.

In the 1960s and early ’70s, revisionist westerns were hardly unusual. The genre was used to taking sideswipes at US involvement in Vietnam and apologising (belatedly) for the crude treatment meted out by white settlers to the American Indian. Few film-makers pushed the revisionism quite as far as Penn, though. Here, tellingly, the Cheyenne call themselves the “human beings”, and it’s the US Army?led by Richard Mulligan’s strutting, preening General Custer?who gleefully massacre women and children.

Scripted by Calder Willingham (whose other credits include Thieves Like Us and The Graduate) from Thomas Berger’s novel, the film unfolds as a rambling, picaresque folk tale. Through various contrived plot twists, Jack yo-yos back and forth between life with the Cheyenne and “civilisation” (as represented by gunslingers, snake-oil salesmen, Bible-thumping zealots, courtesans and saloon bar drunks). He has an ingenuous, child-like quality that prevents him from ever coming to real harm, whoever is massacred around him. Hoffman plays him in the same diffident manner as he did Benjamin Braddock in The Graduate?and in the glamorous shape of Mrs Pendrake (Faye Dunaway), the preacher’s wife who gives him a home (and a bath to remember) when he’s first rescued from the Cheyenne, he has his own frontier version of Mrs Robinson.

Some of the humour here is pretty childish. The scenes where Jack learns he’s an ace shot, befriends Wild Bill Hickok (Jeff Corey) and briefly becomes a lemonade-guzzling gunslinger called the “Sodey Pop Kid” wouldn’t look out of place in a kids movie. Fortunately, countering its own tendency toward whimsy, the film also offers an affecting look at a world in its death throes. Even as they massacre Custer and his men at Little Big Horn, the Cheyenne know that their long-term defeat is inevitable. “We won today but we won’t tomorrow,” Old Lodge Skins (played with humour and pathos by Chief Dan George) tells Jack. We often see the Cheyenne alone in a snow-covered landscape, or sitting forlornly beside their campfires. Many of the greatest westerns are elegiac affairs in which the old world is encroached on, and ultimately destroyed, by the modern age. Here, the sense of nostalgia is given a novel twist by the use of the 121-year-old to bring the west back to life. Jack has outlived everybody. If he is telling the truth, he’s the only remaining survivor of Little Big Horn. Penn plays up the fact that he’s an unreliable narrator and accentuates the comic side of his memoirs. Even the saddest and most squalid moments come laced with humour. Custer’s absurd blustering at Little Big Horn is played for laughs. So is Wild Bill’s demise?when the (by-now) law-abiding cowboy is gunned down in Deadwood by some yokel he doesn’t recognise, avenging some killing he doesn’t remember. But the comedy is there for a distinct purpose. Without it, Jack’s account of genocide and loss would be unbearable. Little Big Man is an East Coast intellectual’s version of a western. “This picture has the character of a primitive tale of the west, yet it is full of deliberate, inaccurate sophistication,” the director has admitted. Penn was to make one more foray out west in 1976, with The Missouri Breaks. The irony is that a film-maker who set out to overturn the clich