Lived fast. Died young. Left a good-looking corpse. The cliché was all but coined for James Dean, who died fifty years ago this September. With just three starring parts, Dean landed a place in Hollywood history, initiated a generation of young men into the torn-shirt school of acting and left behind a great quiff. He’s the only actor to be nominated for two Oscars posthumously – for East of Eden (1955) and Giant (’56) – and more or less patented the whole screwed-up kid role (‘the loser who wins’ he called it) in Rebel Without a Cause. When Dean wailed in close-up to his parents ‘You’re tearing me apart’, he provided a clarion call for disaffected youth the world over. What’s more, he actually lived the life: orphaned, rootless, bisexual. Totalled his Porsche 550 on a desert highway, an overnight legend at just 24. If Dean had lived he’d still be younger than Clint Eastwood is today, and a mere lad compared to Paul Newman.

What would he have become? Quite possibly a bloated parody like his old rival Brando, but more likely a Hollywood burnout. ‘Dean wasn’t a guy you could see aging gracefully,’ his mate Rod Steiger recalled. ‘He gave me his prized copy of Death in the Afternoon by Hemingway. Every line that dealt with death was underlined in red pencil. I saw that and said, "Oh boy".’ Dean ‘didn’t really give a shit about movies,’ Steiger added. ‘All he wanted to do was say the lines and get the hell into the car.’ So even if he’d survived the Fifties, who’s to say he would have handled the Sixties?

Born James Byron Dean on 8 February 1931, he endured both his mother’s death and being raised on an Iowa pig farm before heading to college in California. Dean drifted into acting and was soon recognised as a comer, a prototype of the kind of restless American youth – punks, they were called back then – later nailed by Elvis. Not to his mind, of course. ‘Jimmy thought of himself as not having a great deal of natural talent,’ said Steiger, ‘but as someone who was a powerhouse in the sack. You used to hear him tell women about the eyes being his experience and the hands his soul. Anything to get those panties down.’ In 1951 Dean went to New York and eventually landed a part in Broadway’s See the Jaguar. Two years later he was back on the Great White Way in The Immoralist, forming a professional if oddly tactile friendship with the young Steve McQueen, who in those freewheeling Village days could be as camp as a row of tents. A friend of Dean’s called Paul Darlow allegedly watched the two actors painstakingly comb one another’s hair one night in a room in the Iroquois hotel. Meanwhile, Warner Brothers came knocking with East of Eden, the start of one of the most spectacularly brief screen careers of all time. McQueen took longer to find his feet, shamelessly filching Dean’s angst-ridden act in The Blob (1958) before becoming a sort of male equivalent of the Statue of Liberty.

Dean’s three major roles were basically versions of himself, in which he hinted at a mysterious damage, a tough ‘n tender combo that pop psychologists have largely explained away in terms of his mum. McQueen himself would later trade on much the same mixture of fragility and latent menace. At a time when films tend to be either infantile (Meet the Fockers, etc) or geriatric (the cult of the tortured loner), Rebel and the rest are great entertainment that doesn’t pander – you won’t find any stylized introspection or fart jokes, just richly layered performances that combine earnestness with a little playfulness. The voice, the sense of mood and action would be so well crafted that it would – and does – take sages whole books to even review the underlying sense of pathos, the wounded-runt sensibility Dean could pack into a few tart lines of dialogue. Conversely, by the time Giant came around, he could play it tight and hard in even the most asinine soap opera. Anthony Quinn would scoop the best-supporting Oscar that year for Lust for Life, but Dean’s was the more honest performance: ‘you never caught him acting,’ as Brando put it admiringly.

Early death is often seen as a kind of martyrdom, and Dean’s fatal shunt on 30 September 1955 went a long way to advancing his myth. That Friday afternoon he set out in the Porsche for a rally near Salinas, in the heart of Steinbeck country some 200 miles northwest of LA. A mechanic named Rolf Wutterich accompanied him, and two friends (one of them ‘Wild Bill’ Hickman, who went on to stage the auto scenes in Bullitt and The French Connection) followed in a chase car. At 3.30 pm he was clocked doing 65 mph in a 55 zone and got pulled over by the Highway Patrol. Dean apparently thought it very funny that the cop didn’t recognise him, even after he signed the ticket. Two-and-a-half hours later, just as dusk was falling, a 23-year-old man named Donald G Turnupseed pulled his 1950 Ford off Highway 46 onto Highway 41 near the small town of Cholame. Midway through the turn he was struck side-on by the speeding silver Porsche. ‘I didn’t see him coming,’ Turnupseed said.

Rolf Wutterich was thrown through the windscreen and suffered a broken jaw and leg; he recovered, and died 25 years later in a car crash in West Germany. Dean sustained internal injuries and was pronounced dead in the ambulance headed for hospital. Turnupseed walked away unscathed, and spent the rest of his life fending off interview requests from the curious and the disturbed, while building up a successful electrical supply business based just a mile or two from the scene of the accident. He died of natural causes in July 1995.

James Dean was buried on 8 October 1955. The following day, Rebel Without a Cause was released. Giant followed a year later, a superior kind of Dallas or Dynasty that still holds up surprisingly well today when not mangled over two nights on TV. Defiant, brooding, a sort of cross between John Wayne and Jean Gabin, Dean played the role of a lifetime in his final film, a Europeanized western.

In the years since, countless hopefuls have attempted the trademark Dean slouch, the inimitable hairdo and most notably the anguished mumble, but each has wound up a wan copy of the original. ‘Jimmy was unique, a force of nature,’ Brando allowed. ‘Like Niagara Falls and the Grand Canyon. All you could do was stand back and be awed by it.’ Literally scores of books have been devoted to divining the mystique, but a half-century later he’s as elusive, and ubiquitous as ever. Personally, I always think it striking that Dean died in the same year as rock and roll was born. Most of today’s voguish MTV gods, with their screwed-up nihilism and phony selves, wouldn’t have stood a prayer without him.

Christopher Sandford’s biography of Steve McQueen is available in paperback (HarperCollins, £8.99)