Ill-fated: The tragic decline of Hannah Chaplin haunted the star all his life
Notorious for his under-age mistresses and pilloried for his Leftwing views, Charlie Chaplin will forever be remembered for his tear-jerking performances as the vulnerable Little Tramp - the icon he created in silent movie days.
The endearing figure with his bowler hat, cane and slapstick routines was inspired by Chaplin's poverty stricken childhood in the grim back-streets of Victorian London and the British music halls where he first performed.
And it has always been assumed that the pathos that made the character so memorable had its origins in his father's tragic early death from alcoholism and his own incarceration in a Dickensian-style orphanage at the age of seven.
But now a new book by the renowned psychiatrist Dr Stephen Weissman claims that the real source of Chaplin's sorrow, and therefore his creative juices, was not so much the loss of his feckless father, but the terrible and hitherto untold story of his beautiful mother, Hannah.
Instead of being the loving and glamorous parent Chaplin always claimed she had been, new evidence suggests that Hannah - a minor music hall star who performed under the name of Lily Harley - spent part of her youth working as a prostitute with tragic longterm consequences.
For Weissman claims that she contracted syphilis - a disease not readily curable in the late 19th century - and that it triggered a harrowing descent into madness, witnessed by the young Chaplin who would never be able to forget it.
According to one of his mistresses, silent film star Louise Brooks, it left him so scarred he would never have sex without first painting the appropriate part of his body with iodine to try to prevent any possible infection.
Hannah's fate was so horrible that, until now, Chaplin biographers have fought shy of revealing the details.
Chaplin's own autobiography, published in 1964, has a deeply moving first chapter about the travails of his South London childhood, but he ascribes his mother's mental decay and subsequent incarceration to malnutrition brought about by depriving herself of food in order to feed her sons.
As a result, even Chaplin's children have remained ignorant of the whole truth. Indeed, when his eldest daughter Geraldine, herself a famous actress, learned that a new book was being written delving into her grandmother's sad decline, she first tried to ban publication.
Little Tramp: The character was shaped by Chaplin's hard upbringing
But she soon realised that the new information unearthed by Weissman would cast invaluable light on the source of Charlie Chaplin's genius.
So what was Hannah's story? The daughter of a shoemaker of gipsy stock, she ran away from home at 16 and, naming herself after the famous Victorian music hall star Lillie Langtry, went on the stage.
Soon she had fallen in love with Charles Chaplin Snr, a butcher's son turned actor, whom she met when they were both playing in a popular comic opera.
Always a dreamer and enchanted by the rags-to-riches story of Napoleon's wife Josephine, Hannah said she was drawn to Charlie senior because of his resemblance to the French Emperor.
But three years later she abandoned him and, still a teenager, ran off to South Africa with another lover, Sydney Hawkes, a cockney conman who posed as a rich aristocrat with vast colonial estates.
New research has convinced Weissman that Hawkes was in fact a pimp who took her off to the gold rush boomtown of Witwatersrand and forced her, like many other gullible cockney girls of the time, to work as a prostitute in dance halls servicing the sex-starved gold miners.
Life among the fortune seekers who rushed to the dusty outpost from all over the world was tough, cut-throat and dangerous.
By 1884 Hannah had had enough, and although pregnant by Hawkes, decided to return home to England and look up her old sweetheart, Charles Chaplin.
Hawkes's son, also called Sydney, was born the following year, yet she and Chaplin resumed their romantic relationship and worked together on the London stage.
In 1886 they married and in due course had their own child, the comic genius Charlie Chaplin, born in 1889.
The little boy, who inherited his mother's fantasising streak, would later romanticise his early childhood and the strength of his parents' bond.
He adored his mother, recalling her as dainty and beautiful with violet eyes and fair hair so long that she could sit on it. He loved the way she dressed him in velvet and remembered fondly how she would enact imaginary scenes from the life of one of her many heroines, the 17th century courtesan Nell Gwyn, mistress of Charles II.
But Hannah was not the fashionable actress or the faithful wife that her young son had imagined.
Even Chaplin's children never knew the truth
Soon she had left Charlie's father yet again, this time for a fling with a more famous actor, Leo Dryden, by whom she had a third son.
Hannah now had three boys by three different men, but had managed to fall out with all their fathers.
After Dryden abandoned her, taking their baby with him, she was forced to take stage jobs in ever smaller theatres to feed her two other children. She even had to pawn her glamorous stage gowns to pay the rent.
Her faltering career finally ground to a halt one night when her singing voice cracked and sank to a whisper in the middle of her act and the audience cruelly laughed her off stage.
Charlie, aged five, was listening in the wings, appalled by her humiliation. But, already a talented mimic, the little boy took his mother's place under the spotlight and finished her act.
Film star: Chaplin in City Lights with Virginia Cherrill
In the following months, he would have to cope with far worse. Soon his mother started to develop blinding migraines, accompanied by terrifying hallucinations.
The headaches, which lasted up to a month, made it impossible for her to look after her boys and they were taken into the poorhouse.
When Charlie was seven, he was moved into the orphanage he hated.
This time Hannah recovered sufficiently to get her children back, but from now on she was a changed character.
Obsessed with her failing health she took up religion in an attempt to find a cure. Now, instead of going on stage, she would spend her evenings acting out scenes from the Bible for her boys at home.
Charlie, of course, had no idea at this point what was wrong with his mother and concluded her bizarre behaviour was designed specifically to hurt him.
Not according to his biographer Weissman, who learned Hannah's devastating secret from newly discovered contemporary medical records.
In 1898 she was diagnosed as syphilitic and suffering from the violent psychotic episodes characteristic of the tertiary stage of the disease.
Suddenly, says Weissman, everything fits into place. Syphilis would also have been the cause of her terrible headaches, for they too are a symptom of the ailment.
They can occur up to ten years after the initial infection and Hananh must have contracted it while she was working as a prostitute in South Africa.
Left untreated, the disease took such a toll on Chaplin's mother that by the time she was 35 she was confined to the grim Cane Hill Lunatic Asylum on the outskirts of London, where she had to be kept in a padded room.
On this occasion her sons were sent to live with Chaplin Senior, and though young Charlie amused himself by perfecting impressions of his drunken father and his wayward mistress Louise, he was pining all the while for his absent mother.
The sensitive boy was horrified by her condition
Eventually, Hannah was released from Cane Hill and mother and sons were reunited in a cheap top-floor room next to a slaughterhouse in London's Kennington, where she made a living as a seamstress, setting herself up with a borrowed sewing machine.
This time her income was supplemented by Charlie's father, who had begun to take his paternal responsibilities more seriously.
Young Charlie, too, was encouraged to contribute to the family income by doing what he loved best - performing. Once more, however, his happiness was to be short-lived.
In 1901, his father died of cirrhosis of the liver, aged just 37, and was buried in a pauper's grave.
Then, two years later, his mother had a nervous breakdown and was again hospitalised.
Charlie, by now a sensitive 14-year-old, was profoundly shocked to see her ravings and hallucinations accompanied by an apparently drunken gait - all characteristic of the ravages of tertiary syphilis.
To make matters worse, this time Charlie was left completely on his own in the family flat and was rescued from the squalor in which he was living only by the return to London of his half brother Sydney, now a 19-year-old ship's steward.
The elder lad spruced up the young urchin and took him round the theatrical agencies.
Adored around the world: Chaplin waves to the crowds in Canning Town in 1931
Soon they both had acting jobs and could afford to send money to their mother. But within a year she was found wandering the streets again and was sent back to hospital.
She was now such a pathetic figure that Charlie could scarcely bear to visit her.
Instead, he threw himself into his work, serving an apprenticeship in music halls all over the country and learning the slapstick, burlesque routines that would make him a star.
Though he suffered many setbacks - often booed off stage, just as his mother had been - he finally landed a lucrative contract with the great impresario Fred Karno.
But though Charlie's acting talent was not in doubt, his relations with women were affected permanently by his mother's instability. For a long time he had no idea how to treat girls and his only companions were Piccadilly whores.
And when he finally fell in love with 15-year-old showgirl Hetty Kelly in 1908, he scared her away by proposing immediately.
Then, when Hetty turned him down, he spent the rest of his life fantasising about a rapturous reunion with her.
In the end one of Fred Karno's productions earned Chaplin a ticket to America, where he would make his fortune.
He was now 21, just 5ft 4in tall and weighed little more than 9st, yet so supremely confident that when his ship approached the docks in Manhattan he took his hat off and shouted: 'America, I'm coming to conquer you! Every man, woman and child shall have my name on their lips - Charles Spencer Chaplin!'
The little comic crossed the Atlantic twice before his boast came true. He toured America from coast to coast and claimed to have bedded 2,000 women en route.
Then one night in 1912, his act was seen in New York by legendary producer Mack Sennett, who ran the famous Keystone studios in California. Sennett lured Chaplin West by doubling his salary.
And so, on a rainy day in February, the scrawny newcomer to the Keystone film company started rummaging idly through the communal wardrobe.
There he came across silent star Fatty Arbuckle's huge pantaloons and bowler hat; trimmed down comedian Mack Swain's false moustache; put Keystone Cop Ford Sterling's size 14 boots on his feet and wrapped himself in director Charles Avery's cutaway jacket.
He brought her to America and hired expert carers
Chaplin looked in the mirror and saw the transformation that would make him world famous.
He said he knew the Little Tramp intimately: 'He was myself, a comic spirit, something within me that said I must express myself.'
This was the character formed of his turbulent childhood, of all the roles he had played in the English music halls and of the acute sense of loss he had felt when separated from his mother.
As for Hannah, she never recovered. By 1921, just as her gifted son was starting to make his most famous movies, she was in the irreversible throes of dementia.
Desperate to be reunited with her despite her illness, Chaplin brought her to Hollywood to join himself, her first-born Sydney and her long-lost third son Wheeler Dryden, who was working for Chaplin.
Fourth time lucky: Chaplin finally found happiness with wife Oona
He bought her a house in California and engaged round-the-clock carers. Then he started work on his 1925 film The Gold Rush, almost certainly inspired, according to psychiatrist Weissman, by his mother's early South African escapades.
Weissman believes, too, that Chaplin was prompted to embark on the most poignant of all his movies, City Lights as a direct consequence of Hannah's death aged 65 in 1928.
In it, the Little Tramp falls in love with a blind flowerseller and, putting aside his own feelings, tries to engineer a reunion between her and the millionaire benefactor she prefers - an indication, says his psychiatrist biographer, that the little comic was still yearning for a reunion between his parents more than 30 years after his childhood was torn apart by their separation.
In real life Chaplin himself was unable to settle down until many years later. He famously had affairs with most of his leading ladies - and married three of them, Mildred Harris, 16-year-old Lita Gray and Paulette Goddard.
But he did finally recreate the happy family life he had always wanted. In 1943 when he was 54, Chaplin married 18-year-old Oona, daughter of the great playwright Eugene O'Neill, and fathered eight more children.
One of those was daughter Geraldine, who played her grandmother, Hannah, in Richard Attenborough's 1992 film about Chaplin's genius.
For Geraldine, Weissman's extraordinary revelations have proved particularly heart-wrenching. For, as happens with so many comic stars, her father's bravest of faces hid a truly haunting story.