The western will never again be the mighty, self-sustaining genre it was in the 1940s and 1950s, when Hollywood pumped out hundreds of cowboy films a year. But today's filmmakers are still fascinated by the western's epic scope and endless possibilities, and every now and then someone has a pop at making a modern one.
Next year Johnny Depp will star alongside Armie Hammer in Gore Verbinski's revisionist take on the classic 1950s TV western The Lone Ranger. But this time the Lone Ranger will be portrayed as a clueless dummy, while his long-suffering Indian sidekick Tonto is the brains behind the operation.
Quentin Tarantino, meanwhile, is putting the finishing touches to his first western, Django Unchained. The film, which Tarantino has referred to as a 'southern', is set in the Deep South and will combine the trashy sensibilities of spaghetti westerns with a story about the evils of slavery.
Jamie Foxx will play a freed slave- turned-bounty hunter, and the film is due for release at the end of this year.
But both these new films will be at variance with the traditional values of the western.
Westerns began appearing as early as 1902, when the events they described were still part of a recent and well-remembered past. These rousing adventure films became a popular way of explaining the settlement of the American west, but also of safely mythologising it.
In classic westerns, outlaws, however attractive, were always ultimately punished and summary justice was dispensed with an iron hand by square-jawed and morally unimpeachable sheriffs.
Native Americans were unholy, primal savages who hopped around singing and killing and had unspoken but obvious designs on the white women.
It was all nonsense, of course, however entertaining.
The theft of Indian lands and massacres of native people were nowhere to be found in Hollywood westerns of the 1930s, 1940s and 1950s, and Gary Cooper and Randolph Scott had little connection with the sociopaths and killers who had actually participated in the carving up of the old west.
But from the 1960s on, the western era was radically reassessed in a series of films that became known as revisionist, or anti-westerns.
These movies presented a far more realistic picture of what the Wild West had actually been like.
In the revisionist westerns outlaws were often the good guys, and lawmen corrupt flunkies in the pay of cattle barons.
These films transformed the western forever, and here are some of the best and most influential of them.
THE GOOD, THE BAD AND THE UGLY (1966)
Among the best of the so-called spaghetti westerns, Sergio Leone's sprawling, three-hour epic follows three ruthless protagonists across the charred landscape of Civil War America. Clint Eastwood, Eli Wallach and Lee Van Cleef play three competing bounty killers on the hunt for a character called Bill Carson and a cache of stolen Confederate gold.
Their indifference to the suffering around them as they crisscross corpse-strewn battlefields is sickening, as is the violence they inflict on each other and various passers-by.
Leone's westerns were simultaneously more heightened and more realistic than earlier Hollywood films, and the director said he was trying to depict how the west was made by "violent, uncomplicated men".
THE WILD BUNCH (1969)
Sam Peckinpah's 1969 western is a very interesting take on what by then was a tired and increasingly unfashionable genre. Peckinpah's film is set in Texas in 1913, and follows the slow decline of a group of ageing outlaws led by William Holden, as they begin to realise that the new America has no need for them.
Full of stylistic touches, multi-angle shoots and innovative slow-motion killings, The Wild Bunch felt like an elegy not just to the old west but the western itself, and made one wonder what did happen to all the killers the settlement of the west threw up, once they were no longer required.
McCABE AND MRS MILLER (1971)
Revisionist westerns subverted the conventions and clichés of the genre, and few more radically than Robert Altman's McCabe & Mrs Miller. In most westerns the stranger who comes to town is a dangerous and resourceful hero, but Warren Beatty's John McCabe was just a snake oil salesman.
A wandering gambler, McCabe arrives in a two-horse town called Presbyterian Church and acts the tough guy. A rumour goes around that he's a dangerous gunman, and McCabe then opens a brothel in partnership with an English madam called Mrs Miller (Julie Christie).
But McCabe's bluff is called when some real gunmen come to town, and things end messily in this unusual and decidedly unheroic western.
THE OUTLAW JOSEY WALES (1976)
When Clint Eastwood began directing westerns in the 1970s, he surprised many with the thoughtful and sometimes melancholy way he approached the genre. And in this beautifully photographed 1976 film he debunked many of the myths around the American Civil War.
Eastwood was Josey Wales, a former Missouri farmer who joined a group of Confederate bushwhackers after his wife and son were murdered by Union troops.
Now the war is over but Josey still has a price on his head, and as he searches for a safe haven he gathers a motley group of women and Indians who become a sort of impromptu family.
DANCES WITH WOLVES (1990)
Believe it or not, Kevin Costner's Dances with Wolves beat out Martin Scorsese's Goodfellas to win best picture at the 1991 Oscars. It wasn't that good, but Costner's three-hour epic was an honest and absorbing attempt to explain the west's settlement from a Native American point of view.
Costner was John Dunbar, a Union army lieutenant who's the lone occupant of an abandoned post on the frontiers of Sioux territory. When he helps one of their injured women to safety, Dunbar is welcomed by the tribe, and becomes proficient in their customs and language.
The film's period detail was impressive, and dealt fairly if a little sentimentally with the Native Americans. But critics noted that Costner's love interest was a naturalised white woman, and not an Indian.
If any film finally debunked the glamour of gunfighters and outlaws, it's Clint Eastwood's multi-Oscar-winning western, Unforgiven. When a prostitute is disfigured by two customers in the remote Wyoming town of Big Whiskey, the girls post a bounty on the men that did it.
Enter former gunslinger William Munny (Eastwood), who rides north with his old partner Ned Logan (Morgan Freeman) to kill the men and claim the money.
Gene Hackman plays Big Whiskey's vicious sheriff, and Richard Harris a flamboyant outlaw called English Bob.
But the film makes clear that in most gunfights the protagonists were blind drunk on cheap whiskey, using guns that often exploded in their hands, and won or lost on sheer luck.