Towards the end of his life, Marlon Brando enlivened one dinner party when he stripped naked, “plucked a lily from a vase, stuck it in his rectum, and exited”. Such behaviour was entirely typical, and didn't even require alcohol. Eccentric, amusing, obnoxious, or downright unhinged?

In a crowded market of books about Brando, the greatest of all screen actors, Stefan Kanfer strikes an original note by portraying him, albeit with great sensitivity and tact, as a man permanently teetering on the brink of madness - clearly part of his mesmeric screen presence. “Christ! It was like a furnace door opening,” said John Huston. Brando's entire career was an attempt to hold on to sanity, and the appalling wreckage of his personal life - the bewildering parade of wives and children, the addictions and suicides - was less the result of cruel or indifferent fathering than of an inherited tendency to mania and extreme behaviour. It was a mercy Brando's main addiction was food. If it had been drink or drugs, he'd surely have been dead by 30. And rather than regret that he made so few decent films and squandered such a matchless talent, Kanfer strongly suggests, we should probably be grateful that he made any at all.

He was always an evasive, self-protective joker. In his military-draft questionnaire, under Race he put “human”, and under Colour he put “seasonal - oyster white to beige”. He also told them he was “psycho-neurotic”. The army agreed with him, and he was released. Long before Michael Gambon perfected the fine art of lying to impertinent interviewers, telling them for instance that he used to be a homosexual but had to give it up because it made his eyes water, Brando was revealing that he lived on a diet of nothing but “raw eggs, peanut butter and pomegranates”, or that his reading matter consisted “entirely of Spinoza”.

He was astonishingly promiscuous and juvenile, fond of mooning and given to wooing young ladies by handing them a chocolate bar and suggesting places they might like to put it. He rejoiced in his own crudeness and boorishness, as if careless whether his target went to bed with him or not - though most of them did, “iron filings to the Brando magnet”. Kanfer also shows rather more scepticism about his celebrity conquests than other, barrelscraping biographies, such as the worthless Brando Unzipped, which lists among his numerous lovers Gore Vidal, Leonard Bernstein, Joan Collins, Faye Dunaway, Bianca Jagger, Tyrone Power, Gloria Vanderbilt and Bob Dylan. Bob Dylan? And Brando? My God, they'd look like Laurel and Hardy.

As for the acting, it's astonishing to learn the degree to which Brando created his characters, rewrote the scripts, or improvised as the cameras rolled, having neglected even vaguely to learn his lines. The most memorable touches in The Godfather are his, not Francis Ford Coppola's or Mario Puzo's, even though it seems a ludicrously overrated film now. “Trash given first-class treatment,” one early critic said. But it was Brando who improvised grabbing a stray cat, “stroking it while he gave his lethal orders”, and Brando “who peeled an orange, made fangs with pieces of the rind” and “stuck them in his gums” to amuse his little grandson. In Apocalypse Now, meanwhile, Brando's unscripted ramblings suited the character of Colonel Kurtz to a T.

Brando had his own ideas for the conclusion to Mutiny on the Bounty, too, which would have made the film a far more fascinating and sombre journey into the Heart of Darkness, had they been used. “Evidently affected by Plato's cave in The Republic,” says Kanfer (a literate as well as perceptive biographer), Brando wanted to play Fletcher Christian in the last scene sitting in the mouth of such a cave, brooding silently, while “shadows of rape, pillage and murder would move on the stone walls as the British sailors ruined the natives of Pitcairn Island”. Ironies abound here, however. The 1960s cast and crew filming in Tahiti availed themselves so eagerly of the easy-going locals, “compliant to the point of passivity”, that gonorrhoea ran rife and “an expensive Californian physician had to be flown in with serum and antibiotics”. Whether he treated the locals as well, or just the neo-imperialist American film-makers, is unclear.

Brando's last years were grim. He had a Mel Gibson moment on the Larry King show, declaring that “Hollywood is run by Jews”, though stopping short of Gibson's interesting point about Jews starting all the wars in history. His son Christian shot dead his half-sister Cheyenne's boyfriend by whom she was pregnant; when the baby was born, it had to go straight into “postnatal detox”; in 1995, Cheyenne, vastly overweight, hanged herself. Brando himself died in 2004 at the age of 80, from “obesity, pulmonary fibrosis, diabetes, cardiac failure, and enlarged liver suggesting cancer”. His house on Mulholland Drive was mouldy and in advanced disrepair. He left $21m, but mountains of debts and liabilities.

Late on, Brando confided to a friend that “he had spent a lifetime trying to be less crazy”, a childishly simple and poignant summation of what in some ways seems a monumentally brave career - and Kanfer's biography is a noble monument to it. Brando also said that he only knew true peace once in his life. In 1950, aged 26 and having just finished performing in the acclaimed stage version of A Streetcar Named Desire, he had money in the bank, time off and no commitments. In the few months before he surrendered himself to the talons of Hollywood, he took off abroad for the first time in his life.

He sailed to Europe and made for Paris, where he stayed in a cheap hotel and did a bit of mime on the streets of the Marais. Nobody knew who he was. Then he pushed on south into Italy, bypassed Rome, then in its Cinecitta golden age, and headed down to Naples, as if living a Mediterranean version of On the Road. He was entranced by the Neapolitan girls, “more intoxicating than the local wines”. He walked across Sicily, falling asleep in a field of flowers and waking up to a perfect sunset. After this, he said, “Life would never be pure or unsullied again.”

Somebody by Stefan Kanfer
Faber £20 pp352

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