Death has surely come as a merciful release for Muhammad Ali, for it has ended an agonising 30-year struggle with Parkinson's disease - the one opponent even The Greatest couldn't beat.

Having spoken to many of his friends and family members, I know that, during his last years, each new day was a waking nightmare. He was trapped in a body so dysfunctional that he needed assistance just to stand up, and could only communicate by grunting.

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Ali had become totally dependent on his fourth wife Yolanda - Lonnie - or more usually her sister, Marilyn Williams, who served as his live-in carer during his last years.

The two women would shuttle Ali between his summer house in Louisville, Kentucky, and his winter retreat in the warmer climes of Scottsdale, Arizona, only breaking the routine to fly him to charitable functions and celebrity-studded occasions.

According to some close friends, he seemed to relish the adulation he received when making these poignant, silent appearances; others questioned the morality of wheeling him out to be gawped at like some waxwork exhibit.

Since his face had become an emotionless mask, it was difficult to tell what Ali really thought, yet publicly, as in private he carried his burden with the same courage that saw him through his epic fights with George Foreman and Joe Frazier.

From the time his symptoms first began to appear - when he was approaching 40 years old and still dreaming of winning back the heavyweight title - until he drew his last breath, Ali never displayed an ounce of self-pity.

Occasionally, however, he would vent his frustration by rebelling against the indignity of his condition. He would pretend to have swallowed the cocktail of pills he needed to combat such classic Parkinson's symptoms as tremors and panic attacks, for example, and hide them beneath a flower-pot.

Or he might become unco-operative as his carer Marilyn attempted to dress him for the day, pulling his trademark pop-eyed faces at her choice of outfit - usually a colourful, loose-fitting cotton shirt and slacks - and making it difficult for her to do up the buttons.

For a man who once prided himself on his supreme physique and his razor-sharp wit, and was accustomed to calling all the shots, this child-like behaviour was his one small way of clinging to some semblance of self-control.

Once propped in his big leather armchair, it was a question of how to while away the long hours when his mind was still whirring with activity, but he was mute and immobile.

No longer able to read or write, for many years he would spend hours watching re-runs of his big fights on a mini-cinema-sized television in his living room: the "Rumble in the Jungle" with Foreman and the 'Thrilla in Manila' were his favourites.

By his last days, however, he had tired of re-living past glories and gazed passively at baseball and basketball games.

His illness had made his vocal chords brittle, but they would sometimes loosen sufficiently for him to muster a few words, and he would ask to be seated before his computer to make a Skype call to his beloved grandson, Jacob, 15, the son of his daughter Khalilah Ali-Wertheimer.

His wife Lonnie insists he never lost his zest for life, though she once alluded to the dark depressions he suffered in this limbo-like state.

"He has a lot to be depressed about," she said. "The adjustment [to his lifestyle] has been terrific. But I think he has a sense of who he is and his place in history ... he still has that sense of self and dignity."

Perhaps so, yet for all his towering achievements, his mood can hardly have been enhanced by the knowledge that he would leave a family riven by feuds. They run so deep that it is difficult to imagine how they might come together in the coming days, even for the few hours of his funeral.

Image 1 of 16: World heavyweight boxing champion Muhammad Ali is shown trying to evade kicks by wrestler Antonio Inoki in 1976.

For let us pull no punches here. Yes, Ali was a sporting genius; a fighter blessed with such grace and agility that he transformed boxing into ballet. Yes, he was a man of unswerving conviction, having sacrificed popularity among America's white majority to champion the Black Rights movement, and given up his world title and the best years of his career rather than take part in the Vietnam War.

And yes, he was enormously charismatic, making mockery of his limited education ('I got out of high school with a D-minus: they gave me the minus for winning the Olympics,' he quipped) to charm all and sundry with his slick repartee and acerbic rhyming couplets.

Behind the braggadocio, away from the ring, however, there was another, very different Muhammad Ali.

An Ali whose flaws - among them his susceptibility to sycophancy and weakness for pretty women - wreaked havoc in his personal life, leaving scars so deep they can never be healed.

In boxing terms, his success can be measured by the unprecedented three world titles he won. When it comes to racial integration, the role he played was so pivotal that it arguably blazed the trail that led to America electing its first black president. Yet sadly his legacy to his family is marred by jealousy, bitterness and division.
Married four times, he was a serial adulterer (fortunately for him, such matters weren't reported openly in his day) and though he acknowledged nine children plus an adopted son, there are many others, all across America, who claim him as their father.

Some have emerged from his train-wreck private life in far better shape than others. Having taken up boxing against his express wishes, his daughter Laila, 37, has become a B-list celebrity.

Some of her sisters have traded on their father's name to succeed in business. But contrast their fortunes with those of his only - known - natural son, Muhammad Ali Junior, now 43.

Two years ago, I was appalled to find him living, with his wife and two infant daughters, in one of Chicago's most notorious ghettos among drug-dealers and gangsters.

They are still there today, cramped into damp, sparsely furnished tenement flat provided rent-free by Junior's father-in-law, and surviving on welfare hand-outs and food-stamps. His is a sorry story indeed.

One of the four children born to Ali's abandoned second wife, Belinda Boyd, 'Junior' was woefully neglected by his absentee father as a child, and badly bullied by boys who wanted to prove they could beat up the legendary champion's son.

Perhaps as a result, he is a pitifully lost and confused character who has spent his life alternately trying to live up to his illustrious name - and making a few dollars from it on the side - and to escape it.

During our meeting, over breakfast at a cheap diner he frequents, Junior recalled how, at his father's 50th birthday party, Ali took him aside for what would prove to be their only heart-to-heart conversation.

"He told me he was afraid what might happen to him in the afterlife because of some of the things he's done,' said Junior. 'I told him that whatever had gone on in the past, I still loved him, and his eyes filled with tears."

He was then 21, and says he spent much of the ensuing 20 years trying to rebuild a relationship with his "Daddy".

But he claims to have been thwarted at every turn by Ali's fourth wife Lonnie, who regarded him - unfairly, he insists - as a sponger and banished him from Ali's life altogether after learning how he had tried to sell a pair of his father's boxing gloves.

Though he desperately wanted to say his goodbyes to his father, he says he was kept at arm's length until Ali drew his last breath. Those who defend Lonnie say her main concern was always to protect her husband.

Whenever he phoned and asked to speak to his father, Junior says, he was told curtly that Ali was sleeping or otherwise engaged.

Then there is Muhammad Ali's younger brother, Rahman, 71, who was once inseparable from him. Indeed, Rahman was with the 11-year-old Cassius Clay (as he then was) on the very day he discovered his passion for boxing.

It happened, as he likes to recall, in 1953, when they went together to Louisville police station to report the theft of Cassius's bike. While they were waiting, he wandered downstairs into the police boxing gym, saw the officers sparring, and was instantly enthralled.

Rahman remained at the great man's side as he rose to greatness, and stuck by him loyally during the years when his heavyweight belt was taken away because of his refusal to go to Vietnam.

Yet after Lonnie took over the running of Ali's personal and business affairs, and set about ridding Ali of the hangers-on who had milked his millions and helped reduce him to bankruptcy as his career faded (his own abject business judgment also played its part), he too became an outcast.

Ali's long-time friend Howard Gosser told me how Lonnie even had Rahman arrested on hearing how he had taken possession of the Clay's old family house and removed some of the furniture.

After death of their mother, Odessa, Rahman was in such dire straits that he moved into the ramshackle, clapboard property in Louisville. However, the deeds had been left to Ali - and as his wife held power of attorney over his affairs, she used the law to recover the property, including the missing furniture, Mr Gosser claims.

Cocooned by his illness, one wonders how much Ali - who was loyal to his friends and relatives to a fault - knew about what was going on.

So who is to blame for the tangled mess? Some point the finger at Lonnie, Ali's childhood neighbour, who gave up a promising career with Kraft foods to care for Ali when his illness took hold, and married him in 1986.

Though few doubt her devotion, they say she is keenly aware of his wealth, now said to be around £60million, and sure to accumulate posthumously, like that of Elvis and Michael Jackson.

Others maintain that, by ruthlessly purging his grasping acolytes and wresting control of his financial affairs with great acuity, she saved him from penury, thus making his decline as comfortable as possible.

Though the former heavyweight champion strove to present himself as a patriarchal figure, and clearly loved his disparate family in his own aberrant way, his son Ali Junior says the boxer took after his own father, Cassius Marcellus Clay, a philandering Kentucky artist.

Clean-cut and abidingly polite until he achieved fame, after he married for the first time - to Sonja Roi, a sassy cocktail waitress with whom he spent just one, tempestuous year - everything changed.

Though he converted to Islam, and was no doubt sincere in his faith, he sewed his wild oats at every opportunity. Meanwhile, he quickly divorced Sonja and married Belinda, who was just 15 and working in a Los Angeles bakery run by the Nation of Islam when his roving eye fell on her.

Then came Veronica Porsche, a statuesque model with whom he began an adulterous affair whilst supposedly in monastic training for the Rumble in the Jungle, in Zaire; and finally Lonnie - with countless others in between.

Sonja recently passed away, but the other Ali wives are very much with us and eager to stake a claim to having been his main woman.

Now working as a nurse in Florida, Belinda is said to be ready to publish a tell-all book about their years together. In a new documentary film about the fighter, called I Am Ali, Veronica - while conceding that 'he wasn't a faithful husband' - swears her undying love for him.

But it is Lonnie (who took no part in the film, and pointedly declined to attend the premiere last autumn) who has been with him the longest. She will act as executor of his will.

His send-off will doubtless be a huge global occasion to match those memorable fights, and we can expect at least some members of his family to take ringside seats, alongside the statesman and superstars.

When the service is over, however, the gloves will be off. Then we might see another titanic rumble, as Muhammad Ali's wives and children - legitimate or otherwise - do battle for his legacy.