He was not the first to discover in movies a refuge that otherwise eluded him. He was 15 when he first saw Charlie Chaplin's Limelight. He saw it 15 times, perceiving himself in Chaplin's loneliness and failure, and perceiving, in the Dresden perfection of Claire Bloom, an ideal and a mirage. I must become famous, he thought, so I can meet Claire Bloom.

Anthony Hopkins met Bloom 20 years later when he played opposite her in A Doll's House. By then his crush on her had faded, but he was famous indeed. And his progress was becoming a tale that could have been appropriated by Frank Capra, a journey that would ultimately sound the distinctly American theme of reinvention, which has attracted dreamers to Hollywood movies since celluloid was created.

Now, 56 years into a life that seems to him to be charmed, he believes in the power of believing, is convinced that you can want something so much that the wanting brings it into being. Yet he can't help wondering whether fate will intervene. 'I'm still waiting for God to tell me, 'What do you think you're doing? You go back to Port Talbot. This is a mistake. We meant Tomkins, not Hopkins.' '

Los Angeles seems an unlikely nirvana for a Knight of the British Empire. But it suits a profoundly restless man who wanted, above all, to be renowned and to be free. Hopkins felt at home the moment he arrived there in the early Seventies, a besotted refugee from the English theatre. He bought a flowered shirt, discovered tequila, imbibed so much he thought he was John the Baptist. 'I talked to the sea,' he remembers, 'and the sea talked back.' He stopped drinking long ago, but still responds to the funky exotica that seduced him initially: pink buildings against blue sky, names like La Cienega and Sierra Bonita, humming-birds darting above scarlet bougainvillaea, mustard-coloured canyons dotted with yuccas.

Some people pine for a life that is forbidden. For a classically trained Welsh actor like Hopkins, life in California and the movies is the forbidden life, and to attain it meant bucking the admonitions of Laurence Olivier, the London theatre establishment, and his own barely acknowledged apprehensions about selling out. Yet some of his projects were carelessly chosen. A frolic with Bo Derek in a hot tub and a heart attack while in flagrante with Suzanne Somers in Hollywood Wives were anomalous choices for a man hailed as Olivier's successor (at least, to anyone who had forgotten Olivier's Polaroid commercials). Inevitably these choices rendered Hopkins's career less stunning than his potential.

His 1991 performance as Hannibal Lecter confirmed that he need not choose between making movies and making use of his gifts. Now, after The Silence of the Lambs and Howards End, he can hardly believe the confluence of pictures and events that have made him a Hollywood player. And it may be that his finest performances are the two he gave most recently: as Stevens the butler in The Remains of the Day, whose fear masquerades as indifference, and as the Oxford don C S Lewis in Shadowlands, who learns that the cost of love is staggering, but not too high.

'Time you came back to the theatre and did some serious work,' he was recently told by a man who emphasised each word by tapping his finger on Hopkins's arm. And Hopkins smiled the sweetly bogus smile he calls a Bambi smile while thinking: 'Take your hand off me or I'll slug you.'

He was an only child, born on 31 December 1937, and raised upstairs from his family's bakery. His father and grandfather were the sort of men he would portray, prone to anger and depths of feeling they could not express. From his father he gained appreciation for the big-spirited and the bluntly unaffected. 'Bakers are mad,' his father would say, 'because they can never guarantee the results of anything.'

Dick Hopkins never knew what to make of his son, a delicate child who played the piano or lay on the floor drawing or tramped by himself through the woods. Tony Hopkins fitted in nowhere. He had no friends. 'I felt I was standing on an offshore island, watching the world through high-powered binoculars,' he says.

When he was six he caught pneumonia. That summer he stayed in bed, while his mother kept the steam kettle going. Half awake, he heard Bing Crosby singing on the radio: 'Deep in the Heart of Texas' and 'You Are My Sunshine'. The music seemed to arch through the sunlight, taking on a hallucinatory quality. His grandfather brought him books about America. 'It was like a dream,' he says, 'with trappers and Indians and great beautiful head-dresses.'

The next summer, American soldiers came to town in trucks and armoured cars. They were looming figures, bristling with energy and generosity, tossing packs of cinnamon and cherry gum at schoolchildren. The energy the Americans personified never left him. 'It created in me a yearning for all that is wide and open and expansive,' he says. 'Something that will never allow me to fit in in my own country, with its narrow towns and narrow roads and narrow kindnesses and narrow reprimands.'

Bewitched by America, he studied the shapes of American cars, watches, pens. 'I knew how many floors the Empire State Building had. I knew all about Yellowstone Park.'

His mother would find him staring at sepia-toned photographs of skyscrapers. 'What are you looking at?' she would ask. And he would answer: 'I want to be there.'

Anthony Hopkins was 15 when he knocked on the door of Cissie Jenkins, whose house guest was her brother, Richard Burton, Port Talbot's most celebrated son and the star of The Robe, which Hopkins had just seen at a local theatre. Burton was shaving when Hopkins entered the house. Timidly, he requested an autograph. As he trudged home, Burton sped by in his Jaguar. Isn't that glamorous, Hopkins thought. I wish I could be like that.

Hopkins's parents had hoped that boarding school would end his isolation. But the troubles he had with his studies only caused the other boys to make fun of him. The five years he spent there, he recalls, were 'the loneliest years of my life'.

At home he played the piano. 'Get out of the house,' his father said one night. 'Go to the Y. Make some friends.'

At the Y they were rehearsing an Easter pageant. 'Can you act?' the director asked.

Standing onstage, Hopkins felt confident for the first time. At last, he thought, I've found something I may be able to do with my life. His other thought was, I'll show them.

Showing them was, in many respects, surprisingly easy. He was accepted at the Cardiff College of Music and Drama on the day in 1955 that James Dean died. In 1958 came national service.

After that, needing acting technique and still uncertain whether he had talent, he applied to the Royal Academy of Dramatic Art, where he established himself as the leading student. He had already discovered alcohol, heading to the pub at night, staying up on caffeine tablets and driving himself too hard, his exhaustion revealed in sudden outbursts. In 1965, working in repertory, he was given the chance to audition for Olivier. The night before, Hopkins saw him play Othello. 'What will you do for your Shakespeare?' Olivier asked.

'Othello,' said Hopkins.

Olivier smiled, taking Hopkins's measure. 'You've got a bloody nerve,' he said.

After the audition Olivier said: 'I don't think I'll lose any sleep tonight, but I think you're awfully good. Would you like to join the company?'

Soon, Hopkins's name was the answer to the most frequently asked question in British theatre:'Who will take up Olivier's mantle?'

Hopkins's gifts were suited to the theatre. His temperament was not. The same nerve and vitality that enabled him, on his return to the National Theatre in the mid-Eighties, to bring off what he calls 'the act of madness' of alternating 200 performances as King Lear and Mark Antony also ensured that he would feel trapped performing the same roles night after night. The same standards that lent his work such eloquence in the eyes of others caused him to view that work as desperately inadequate. 'Shakespeare's so bloody difficult, and I don't like failure,' he told his biographer, Quentin Falk. 'You can fail on film, but there's nobody actually there in the flesh to watch you failing.'

In 1971 he was infuriated when Olivier replaced him with Christopher Plummer as Danton in Danton's Death.

'Why did you do it?' Hopkins demanded.

'Because he's a star,' Hopkins recalls Olivier saying, 'and you're not.'

In a sense, he was damned either way: He wanted big parts, but they unnerved him, while small roles left him hungering for centre stage. In 1973 he was playing Macbeth, when he was told to take a minor part in The Misanthrope. The play was directed by John Dexter, whom Hopkins describes as 'brilliant and savage'. During rehearsal, as Dexter screamed at actors and berated them, Hopkins thought, I won't put up with it. In the middle of his contract, he walked out on the National. Olivier worried that Hopkins would end up like Burton, making movies and drinking so much that his scenes finally had to be shot before what was euphemistically called lunch. 'And,' says Hopkins, 'that's about what I did.'

In the United States he was acclaimed in Equus on Broadway, then went on to California. It was the early Seventies, and by this time drinking had left him wildly unpredictable. He would say he was leaving home for half an hour and return a day later. 'I was crazy and tired and frightened,' he says, 'and my wife was frightened of me.'

In the winter of 1975 Jenni Hopkins, who is as moderate as her husband is intense, returned to England for Christmas, giving him room, he later told David Frost, 'to polish myself off or sort myself out'. He awoke in a motel in Phoenix, Arizona, without remembering how he got there. Back in Los Angeles, he went to a party at the home of the actress Michele Lee, where he quietly played the piano until he passed out beneath it. The next day he walked into an office of Alcoholics Anonymous. He never drank again.

In his drinking days he was, by his own account, 'gentle and very violent'. The violence is gone, but he is still two-sided. One moment he hikes through a canyon, thinking, I can retire, have some fun. Hours later, his thoughts on work, he worries about what he will do next.

'The charm built in to most Welshmen - he exudes that,' says Lauren Bacall, one of the few people whose company he seeks. 'But there's this tremor underneath, an underlying intensity, like a volcano. The lava doesn't erupt, but it moves.'

The same quality infuses his work. 'Tony has what all the great figures in the movies have,' says Richard Attenborough, who directed him in A Bridge Too Far, Magic, Chaplin and Shadowlands. 'Cagney, Tracy - however gentle, however comforting they are, you feel that in there is a bomb waiting to explode, that if the moment came, the screen would shatter in front of you. Tony has that, and a lot of very good actors, some of the leading big stars, do not have what Tony has.'

Early in his career Hopkins agonised over technique. Now he trusts more in his eye for human details and his gift for mimicry. As a boy he left movies talking like Bogart and walking like Cagney. Now his screen work contains tributes to other actors: The moment in Howards End when Henry Wilcox loses himself gazing at Margaret on the staircase was taken from the moment in Ship of Fools when Oskar Werner loses himself gazing at Simone Signoret. His ambling walk at the end of The Silence of the Lambs was a tribute to Marlon Brando. 'If it hadn't been for American movies,' he says, 'I wouldn't have wanted to be an actor.'

He had longed to be in a hit movie. He saw the potential in The Silence of the Lambs. In Clarice Starling's relationship with Hannibal Lecter, the imprisoned serial killer, he saw a defiance of all the rules of convention. 'No man will go near this other man,' he says, 'so they send a woman in.' He understood monsters intuitively; empathising with their unbreakable isolation, he had always felt drawn to them. But in Lecter there was also something attractive and strangely sexy. 'A man who's caged, masked, sort of in bondage, being trussed up - a man who has power,' he says. 'This dark guardian at the end of the tunnel who is terrifying and yet can save you.'

On an autumn day he hurries down New York's Fifth Avenue, the beard grown for his role in Alan Parker's The Road to Wellville allowing him to pass unnoticed by a long line of people waiting to enter a showing of The Remains of the Day. He is on his way to a television interview to promote Shadowlands, which is being taped in a Chelsea bookstore.

As he sits on a stool answering the usual questions, his presence in the shop becomes known on the street. Soon dozens of faces peer in the window. This is his audience, an eclectic mix - those who went to The Silence of the Lambs are not necessarily the people who attended Howards End. But now they gather: workmen, young mothers with kids in tow, a man in a Burberry trench coat, fashion victims carrying bags from Barneys, an English photographer in a black leather jacket. Together they stare at this man who is now established as a romantic character actor, a conflation that is usually an oxymoron. Three decades into his career, Hopkins has arrived at that point where the only person he needs to top is himself.

Anthony Hopkins is driving on San Vicente Boulevard, recalling Laurence Olivier's funeral. The year was 1989. Asked by Olivier's widow, Joan Plowright, to recite the last lines of King Lear, he did so, standing at the foot of a coffin blanketed in bluebells and larkspur and Queen Anne's lace. Later he watched the casket proceed to the crematorium, borne along on a gurney, concealed behind a curtain that followed the coffin in spasmodic jerks. This is Olivier's final curtain, he thought.

'I love life,' he says now, 'because what more is there? Nothing lasts, really. There's going to be darkness, and it's all over. That's the wonderful comfort. You think, well, what's the big deal? There's no big deal, in a way. There's a kind of release in that.'

As he drives, the gloaming settles on Los Angeles. The scenery appears backlit. A glow emanates from every eucalyptus and frangipani, and the Pacific shines beyond the looming sugar palms on Ocean Avenue. It was this ocean he had looked at long ago. 'The sea had that tremendous, undulating calm,' he recalls. Gazing at it, he had felt peace. All I ever wanted, he thought, was this.

But there were other things he wanted and, now that he has them as well, he feels compelled to seek explanations.

'I'm more and more convinced that life is a dream. What has happened to me is surely a dream.' He drives a moment in silence. 'Do you think it will last for a bit?'

(Photograph omitted)