The scene was the firstclass dining car of the Brighton Belle on a summer morning in 1964, an era when it was still possible in Britain to travel by train with some degree of civilised elegance.
The tables were draped with laundered, snowy-white cloths and adorned by miniature gold standard lamps with discreet pink shades. Orange curtains hung at the windows, and the walnut-panelled carriage walls were mounted with the royal coat of arms.
"The usual, dear boy," announced the man opposite me to the hovering steward. No one needed to enquire about the identity of my table companion. He was instantly recognisable to everyone as the most celebrated actor in the world: Sir Laurence Olivier, soon to become The Right Honourable Baron Olivier of Brighton.
"I'm very sorry, Sir Laurence," stammered the steward, "but I'm afraid the kippers are off today."
"Off?" The word exploded with such force and menace that the carriage fell silent. "There are no kippers?" asked the great man, his voice rising histrionically. His arms rose also, in supplication to invisible gods. "Great heavens! How can this be possible?"
We all gazed back in wild surprise as the unmistakable tones that had rung through my childhood, urging: "Cry God for Harry, England and St George", now wrung our emotions beyond endurance over the absence of his cherished kippers from the menu.
Sir Laurence's outburst had immediate effect. The Brighton Belle's departure was delayed while a crisis conference took place on the platform. Porters ran panting into view. Trolleys were heaved. As if by magic, a crate of kippers materialised from thin air.
"My darling boy!" cried Olivier, pulling the startled steward into a bear-like embrace and planting a loud, smacking kiss on both his cheeks. The white-coated youth turned slightly pink but showed no other sign of thinking this at all unusual.
As the 55-minute journey to London got under way, I became uncomfortably aware that Olivier had switched his attention from the steward to myself. Every time I looked up from the morning paper, I found his eyes, dark and hypnotic, trained on my 23-yearold face like a searchlight.
Not a word was spoken between us. Had it been any other man, I would have construed such intense interest as sexual. But the cinema's brooding and virile Heathcliff? The great actor who had made passionate love on screen to Marilyn Monroe? The husband of three famous actresses, and the father, in time, of four children? Surely not.
I was so unnerved by that long, silent stare that on arrival at Victoria, I invited myself for a drink at the Chelsea home of one of Olivier's close friends and contemporaries, the actor and playwright Emlyn Williams.
Emlyn, who was also married, with two sons, was bisexual. In his youth, he had been the lover of Olivier's rival in the art of great acting, Sir John Gielgud, before the latter's arrest in 1953 for importuning in a public lavatory.
So diverted was the mischievous Emlyn by the rumours of the homosexual, sado-masochistic adventures of a third great actor, Sir Michael Redgrave, that Williams once accosted him on Waterloo Bridge with the words, "Michael Redgrave, I'll be bound!"
As the story of my encounter on the Brighton Belle unfolded, a broad and delighted grin spread across Emlyn's puckish face. "We all know Larry," he guffawed. "Do I think he is sexually attracted to men?" He let out a snort of laughter. "Is the Pope Catholic?"
Yet for more than 40 years, the truth about Olivier's bisexuality has been subject to denial, prejudice and an extraordinary kind of censorship.
All this changed dramatically last weekend when Olivier's 76-year-old widow, Dame Joan Plowright, a woman of singular honesty and common sense, ended years of circumspection about the sexually ambiguous private life of her late husband in a remarkable interview with Sue Lawley on the radio programme Desert Island Discs.
Dame Joan, herself an acclaimed actress, who was married to Olivier for 28 years, responded calmly to Lawley's references to allegations of homosexual liaisons in the great actor's life.
"If a man is touched by genius, he is not an ordinary person," said Plowright. "He doesn't lead an ordinary life. He has extremes of behaviour which you understand and you just find a way not to be swept overboard by his demons. You kind of stand apart. You continue your own work and your absorption in the family. And those other things finally don't matter."
These infinitely wise words have waited many years to be spoken. They bring to an end a bizarre cover-up of the truth about Olivier.
The 'demons' to which Dame Joan alluded began early in the life of Laurence Kerr Olivier, born on May 22, 1907, at 26 Wathen Road, Dorking, in Surrey. He was the third and youngest child of the Reverend Gerard Kerr Olivier, an impoverished Anglican priest, and his wife, Agnes Crookenden.
Larry's adored mother died of a brain tumour aged 48, when he was only 12. "She was my entire world," he said later. "I cried just at first, but never again. I felt it appallingly deeply."
He made his first appearance on the stage aged 13, in the leading female role of Katherina (the shrew) in a school production of Shakespeare's The Taming Of The Shrew. Larry was so effective as this most coquettish of girls that he was singled out for lavish praise by the greatest actress of the day, Dame Ellen Terry, who said she had only ever seen one woman who had played the part better.
From the beginning of Olivier's life, there was confusion over his sexual identity. The most intimate friend of his youth was the actor Denys Blakelock, also the son of a clergyman, who was homosexual.
Writing years later of their relationship, Olivier admitted he "embraced this unaccustomed happiness with an innocent young gratitude".
The night before Olivier's first marriage, in 1930, to the actress Jill Esmond - a strange coupling, for she was hardly marriage material and ended her life as a lesbian, living with another woman - Denys Blakelock, who was to be his best man, climbed into Olivier's bed, where Blakelock's hands "strayed". Olivier admitted this but insisted the full sex act did not take place.
Just before his marriage to Esmond, Olivier met the reigning enfant terrible of West End theatre Noël Coward, who gave him a contract for £50 a week to play the second male lead, supporting Coward and Gertrude Lawrence in Coward's new play Private Lives.
At their first meeting, Coward was sitting up in bed wearing Japanese silk pyjamas, finishing his breakfast. He called Olivier "Larry", Olivier called him "Noël", and the two men - Coward was the elder by six-and-a-half years - were soon on familiar terms.
Doubts have been cast on the possibility of a sexual relationship between Coward and Olivier, but as one who was close to "The Master" for the last 13 years of his life, I must beg to differ. My authority is a good one: Coward himself admitted that on his part it was "love at first sight" and that sexual familiarities occurred between them "with some regularity".
"At the age of 23, he was the most staggeringly beautiful creature I ever saw in my life," Coward told me, "but although he was struggling to be what he thought of as 'normal', he had a puppy-like acquiescence to all experiences."
In spite of his liaison with Coward, Olivier's marriage to Jill Esmond went ahead, though it seems likely that she made some sort of pre-marital admission of her own bisexual inclinations.
Their son Tarquin was born on August 21, 1936, but by then the marriage was doomed. Olivier had met not only the feline, green-eyed, 22-year-old actress and beauty Vivien Leigh, who was to be his nemesis, but also his most unlikely homosexual partner, Henry Ainley.
Ainley was a 57-year-old married actor and father, who had appeared with Olivier in the 1936 film of Shakespeare's As You Like It.
Ainley, who was clearly besotted by Olivier, wrote to him as "Larry darling" and "Larry Kin Mine", signing himself, "Your sweet little kitten, Henrietta". In one letter he says: "How Jill must hate me, taking you away from her!"
But by that time, Olivier didn't need to be taken away from his wife. His marriage had died under the sustained onslaught of the ambitious and predatory Vivien Leigh, who waged a determined campaign of seduction.
The late actress Phyllis Konstam, who had appeared with Olivier on Broadway, and who was a friend of mine, told me: "No one could have been more wicked than Vivien. She set out quite deliberately to destroy that marriage, and, of course, she succeeded."
Jill Esmond divorced Olivier for adultery on January 29, 1940, citing Vivien Leigh. Jill was awarded custody of the three-and-a-half-year-old Tarquin. After Vivien's husband, Leigh Holman, had also filed for divorce, citing Larry, she became the second Mrs Laurence Olivier on August 31, 1940.
Even before that, however, during the Hollywood filming of her Oscarwinning role as Scarlett O'Hara in Gone With The Wind, Vivien had exhibited the first symptoms of manic depression, the malady that was to turn her marriage to Larry into a Gothic nightmare.
Olivier's starring role in Alfred Hitchcock's film of Daphne du Maurier's novel Rebecca was like an eerie prophecy of what his life with Leigh would become.
As the handsome, brooding and sexually uncertain Maxim de Winter, haunted by his marriage to an ambitious, promiscuous and wicked beauty, he tells her placid successor, with whom he finds contentment: "You thought I was mad. Perhaps I was. Perhaps I am mad. It wouldn't make for sanity, would it, living with the Devil?"
And a devil is what Vivien increasingly became as her tragic illness developed. Outwardly the Oliviers were the most gilded couple in international show business.
Yet Vivien, plagued by mental breakdown and tortured by professional jealousy at Larry's superior talent, became an alcoholic and a nymphomaniac, often pursuing total strangers as sexual partners.
It was small wonder that Olivier continued to turn to men. In 1940, he had met the American comedian and future Hollywood film star Danny Kaye, with whom he had a long and flamboyant relationship. Olivier's official biographer, Terry Coleman, regards it as "unsubstantiated", but I have no doubt that it existed.
The Queen's late aunt, Princess Marina, Duchess of Kent, who was involved with the bisexual and married Kaye for several years, told me quite emphatically that he and Olivier were "épris" ("in love").
And Coward, who was appalled to witness the two men openly exchanging French kisses in public, despised Kaye, whom he habitually referred to as "randy Dan Kaminski" (David Daniel Kaminski was Kaye's real name).
In 1950, when the Oliviers returned to Hollywood for Vivien to film her Oscar-winning role as Blanche du Bois in A Streetcar Named Desire, opposite Marlon Brando, David Niven walked into the garden of their Hollywood mansion and discovered: 'Brando and Larry swimming naked in the pool. Larry was kissing Brando. Or maybe it was the other way around.
"I turned my back to them and went back inside to join Vivien. I'm sure she knew what was going on, but she made no mention of it. Nor did I. One must be sophisticated about such matters in life."
In 1955, with his marriage to Vivien dead in the water, Olivier met the 28-year-old theatre critic Kenneth Tynan, who had been openly disparaging about Leigh's acting abilities.
Both men were officially "straight", yet they formed an intense and passionate relationship which - whether or not it became physical - was certainly homo-erotic in style and content. Tynan's widow, Kathleen, writes: "Both men had in common a need for intimacy and a talent for occasion, for adventure."
Tynan's view of Olivier was: "He's like a blank page and he'll be whatever you want him to be. He'll wait for you to give him a cue, and then he'll try to be that sort of person." This goes a long way towards explaining Larry's fluctuating sexuality.
As Larry's marriage to Vivien reached its final oblivion, Olivier was performing, in Spartacus, the most notorious gay scene Hollywood had yet filmed.
As the Roman General Marcus Crassus, the half-naked Olivier is suggestively bathed by his equally half-naked body-slave (the firmly heterosexual and wildly miscast Tony Curtis).
The scene was regarded as so shocking in 1960 that it was cut from the final film. It was not reinstated until 1991, two years after Olivier's death, when one of his best mimics Sir Anthony Hopkins dubbed his pointedly bisexual dialogue: "Some people like oysters, some people like snails. I like oysters and snails."
Vivien Leigh, arriving at Heathrow airport in a picture hat, was surrounded by reporters. One of them asked: "And how about your private life, Lady Olivier, if one may enquire?' Vivien, with the regal disdain of an empress, replied: 'One may not enquire."
She divorced Olivier on January 6, 1961, devastated that she, one of the all-time great beauties, was being supplanted in his life by Joan Plowright, who - while attractive and an excellent actress - had no claim to beauty.
Larry and Joan married quietly in Wilton, Connecticut, on March 17, 1961. She was to bear him a son, Richard, and two daughters, Tamsin and Julie-Kate.
With Plowright, Olivier was to find a deep inner contentment, a peace of mind and a stability he had never known before. If the 'demons' were not wholly banished, they were certainly sidelined. And if Larry's eye still sometimes strayed in the direction of a handsome young man, Joan had the wisdom, intelligence and tact to ignore it.
After Lord Olivier's death on July 11, 1989, aged 82, from neuromuscular disease and cancer, and his interment in Poet's Corner, Westminster Abbey, his official biographer, Terry Coleman, asked Plowright if he had had homosexual affairs. She replied robustly: "If he did, so what?"
Tarquin Olivier, Larry's elder son, 'was hell-bent on censoring' the homosexual revelations in Coleman's book and attempted to pressure Plowright into withdrawing her permission. She refused, privately remarking that "a man who had been to Eton and in the Guards might be expected to be a little more broad-minded".
As we look forward to celebrating the centenary next May of the birth of Olivier - the greatest actor in living memory - we should also salute the loving intuition and courage of his widow in allowing his complex life to be viewed at last with dispassionate calm and without the distortions of prejudice.