In Martin Luther King’s Why We Can’t Wait, he recounts how a young black man – the first victim of capital punishment by gas chamber in the southern states – had a microphone placed with him within the sealed chamber for the purposes of scientific observation. As the lethal gas pellet dropped, the only words heard through the microphone were “Save me, Joe Louis. Save me, Joe Louis. Save me, Joe Louis...”

As this poignant vignette illustrates, before the days of the Tysons and Mosleys – before boxing fell completely into the sordid little mitts of shameless hype-merchants – boxing champions commanded more awe and respect than the office of the President. Indeed, boxing was truly regarded as the sport of kings, not merely because its origins lay in the aristocratic world of the Marquis of Queensbury. Granted, boxing was never an unsullied affair, carrying connotations first of slavery and later of organised crime, but boxing champions, particularly those belonging in the heavyweight division held a place in the collective imagination that was something akin to a god or a superhero.

As such, when Floyd Patterson, the great gentleman of boxing, faced Sonny Liston – a proto-Tyson, a man whom Americans regarded as a contemptible brute – entered the ring on September 25th, 1962, he had been given orders from John F. Kennedy that he must not lose. What is often forgotten in the warm, fuzzy haze of nostalgia which typically surrounds this period, is that two years later when the then Cassius Clay challenged Liston for his title, he entered the ring not merely as 7-1 underdog, but very much as America’s second choice. Liston’s image was still beyond redemption, and he was still regarded as an articulated truck of a man – not simply in respect to his capacity for physical force, but with respect to his capacity for feelings and intellect as well. Liston in 1964 however, was an infinitely more desirable champion than Clay.

Ali obliterated the stereotypes he was expected to conform to – he was radical, mouthy, shocking, obscenely self-confident, a shameless self-mythologizer, a deluded Don Quixote – the ultimate “uppity nigger” as far as the establishment were concerned. And this was before his conversion to the Nation of Islam and his refusal to go to Vietnam.

By 1996 however, when Ali lit the Olympic torch at the Atlanta Olympics, his hand shaking from the debilitating effects of Parkinson’s disease, what could have been a cheap emotional punch turned out to be the most affecting moment of the Games, which confirmed the radiant Ali’s status as possibly the most beloved person on the planet.

Needless to say, Ali’s journey from irritant to hero has been an eventful one, encompassing his initial shock defeat of Liston, his conversion to the batty Elijah Muhammad’s Nation of Islam, his draft-dodging, his even more shocking defeat of George Foreman in 1974’s Rumble In The Jungle, his gruelling fights with Joe Frazier and his eventual diagnosis with Parkinson’s.

Aside from these bare facts, there’s Ali himself – all too human despite his unassailable standing in history. He had a monumental personality with a libido to match, (Ali called the girls who pursued him his “foxes”, Malcolm X pointed out that they were more like wolves) and a wit typified by the same beautiful cruelty that he displayed in the ring.

He could often prove too much. His taunting of Joe Frazier in the lead up to the Thrilla in Manila in particular, was perceived by Frazier as erring on the side of nastiness. – “What will the people of Manila think? We can’t have a gorilla for a champ. They’re gonna think, looking at (Frazier) that all black brothers are animals. Ignorant. Stupid. If he’s champ again other nations will laugh at us.” While most people recognised such over-the-top goading as Ali’s trademark pre-fight repertoire (inspired by the contemporary pro-wrestler Gorgeous George Wagner), Frazier and sportswriter Mark Kram – author of the recent mean-spirited biography Ghosts Of Manila – failed to see the joke.

As such, the new film biopic of Ali is as risky and potentially disastrous an enterprise as has ever been undertaken in cinema. Director Michael Mann (Manhunter, Heat, The Insider) was under no illusions at all about the intimidating magnitude of the task at hand: to condense the most remarkable story in the history of professional sport into a bite-sized two-and-a-half hour film, while doing justice to the phenomenon.

While documentary movies have been made about Ali – most notably the greatest and one of the best films of the last decade Leon Gast’s 1996 Oscar winner When We Were Kings – the biggest difficulty attendant to making a biopic was casting.

No-one really thought it could be done, least of all by Will Smith, former star of such undistinguished fare as Independence Day and Wild, Wild West. Smith was hardly a plausible heavyweight in physical or acting terms. As he says himself , “Very few people thought this was a good idea”. Ali did though. He called Smith up to tell him so. It turned out to be a good call. Smith gives such a brave and mature performance that Ali turned to long-time friend Howard Bingham upon seeing Smith’s performance and asked, “Man, how come you didn’t tell me that I was so crazy?” With Smith’s turn attracting such lavish praise, small wonder he’s expected to pick up an Oscar come March.

Moviehouse caught up with the actor recently to discuss being punched, being intimidated and being Ali.

Given that Smith has always looked – no offence – a bit on the weedy side – how on earth did he set about becoming a plausible looking Ali?

“Essentially we trained for 12 months. I had a little sneaky month before that where I crept out by myself to try to get into some sort of shape. Little bits – so Michael Mann would think that I was already in good shape. So probably 12 or 13 months of training, and essentially we would run at 6am for three to five miles in the morning, depending on the day, and we would go into the boxing gym from 10.30am to1.00pm. Technical boxing training, jumping ropes, sparring, and then in the evening we would go into the weight room for physical weight training. So that was five or six days a week for a year, so your body would definitely come into shape with that kind of regime.”

How did he manage to take blows raining down from former heavyweight champions like Michael Bentt (who plays Sonny Liston in the movie) during the shoot?

“There’s a really strange primal thing that happens when you get punched. When you get hit there’s a blue flash and you start trying to remember where your car is! ‘Where did I put my keys? As soon as this buzzing goes out of my ears, I’m outta here!’. But when you get hit and you get knocked down and you stand up, there’s a really animalistic thing that happens inside of you and it either destroys or reaffirms your manhood. The first time Michael Bentt hit me, he hit me really clean and I saw the punch coming and I sort of put my chin down. I felt an electrical shock from the base of my neck down to the back of both of my elbows! I remember thinking ‘Damn that Michael Mann!’

“But it felt like a rite of passage to the commitment that we had all made to Muhammad Ali and to telling Muhammad Ali’s story, so it almost felt like I was worthy now after getting hit, to be in the ring with all the champions. We didn’t use any actors; we only used professional fighters so that sort of confirmed my worthiness, in my mind at least.”

Does he remember what he felt about Ali growing up?

“That was what was really important to me about telling this story. I’m 33 years old so I was born September 25th 1968, so by the time I was even paying attention to fights, Muhammad Ali had already finished fighting. I knew he was important, but I didn’t know why. That was part of what inspired me to want to tell this story because anyone that is younger than me has no idea what Muhammad Ali had to endure in his life. So I really was inspired to tell this story, however terrified I was!

“I mean I felt physically perfect to tell the Muhammad Ali story. I felt that I could put the weight on, and that I could look like him. I felt that I could physically become Muhammad Ali, and I felt spiritually akin to his transformation from being in a place where he believed in God through a man (the prophet Mohammed) and elevated himself to an individual one-on-one relationship with God. So I can relate to that transformation. I can relate to that spiritual space and I have always felt not unlike Muhammad Ali in the simplicity of his spiritual beliefs.

“But at the same time I was terrified by the prospect of being the guy that messed up the Muhammad Ali story. They would say ‘Independence Day, that was good! Men in Black, that was cool. But that’s the dude that messed up the Muhammad Ali story!’. So, I was terrified by that prospect, until I met Michael Mann.”

Would he have considered the role if Ali hadn’t asked him personally?

“Well, I turned the script down for years. Probably for six years. I think I was probably 27 the first time a script was presented to me. I just turned it down for years and years. I couldn’t see the road from Will Smith, Fresh Prince of Bel Air, to Muhammad Ali. Someone said, ‘You have to become Muhammad Ali’. I didn’t know what I would do that first day. What do you do to become Muhammad Ali? Michael Mann was the first person who illustrated what he called the “course syllabus” for becoming Muhammad Ali. He said, ‘I will create the curriculum that will create Muhammad Ali inside of you’ and I was like, ‘Alright, cool!’.

“He said we are going to run the way Muhammad Ali ran in the cities that he ran in, on the routes that he ran. We are going to eat the food that Muhammad Ali ate. We are going to spar the way he sparred. We are going to go get Angelo Dundee and train the way Muhammad Ali trained. And by we, he meant me! He said from creating the physical life and the physical burden of a fighter and that physical burden of Muhammad Ali that that would take us to the second tier, which would be the mental and emotional development of Muhammad Ali. And he said by understanding what it feels like to be in a ring, and when that bell rings, and you know that there’s an animal on the other side of that ring that wants nothing more than to tear your head off, you will understand that mental and emotional stress that Muhammad Ali lived with on a daily basis, which would naturally carry us to the third tier which would be the spiritual development.”

Was there a moment during that year of preparations when he finally knew that he had become Ali?

“You know there were moments that information created an epiphany. I don’t specifically remember a moment where I said, ‘I got it, I’m Ali’ I don’t remember that moment. It was such a gradual process for me, I’m glad you saw it! I don’t specifically.

“I remember Michael called in a guy called Jeronimo, formerly Jeronimo Pratt, of the Black Panthers. He came in and sat down and Michael called him in to give me a sense of the era because that was what was really difficult for me. The comprehension of the ’60s is so foreign. I’m a child of rap music, cars and women so I just cannot relate to the social upheaval of the ’60s.

“Jeronimo said that war had been declared on black America. Fire hoses, dogs, domestic terrorism, the bombing of the church in Birmingham, Alabama. He said war had been declared and when he said that, I just felt a wave of understanding. Of course, Muhammad Ali had not gone to Vietnam to fight a war when in his mind, he’s fighting a war right here at home and if he goes 10,000 miles away women and children aren’t safe here in America. One war at a time.

“With that point of view, I started to feel the dominoes begin to tumble towards becoming Muhammad Ali and understanding the necessity for that point of view. The necessity for this hero during that era.”

What does he think about the place boxing holds in American society and history?

“I think also in America, what happened in boxing in the early ’20s, ’30s and ’40s and in any society where there is a group of people that had been colonised by another group of people, the boxing ring is the only place that is fair. For Jack Johnson, for Joe Louis, for Muhammad Ali, the boxing ring represented the only place that racism didn’t matter. Because when Johnson hits you with that right hand, no matter how racist you are, you’re asleep!

“It represented a place where it was man to man, it was one on one and there was no perceivable way to cheat. So I think that’s a large part of the reason why people tend to gravitate towards the boxing match as a true test of man to man. There is no room for the referee to fly a flag; you can’t get a red card! There’s none of that, it’s one to one, man on man. Or woman to woman! Absolutely!”

With all the method preparation – did any of Ali’s mannerisms stay with you after the shoot?

“Yes, the pure appreciation of beautiful women. That has stayed with me. The momentos, I kept everything. All of the clothes, all of the gloves, everything I could sneak into my trailer. I knew from day one that this would be a journey that I would remember for the rest of my life. When we got into Africa we had the opportunity to sit with Nelson Mandela and at every turn in making this film I just had new experiences and was being enlightened. I was keeping everything that I could get my hands on.”

What about the distinctive vocal mannerisms of the Louisville Lip?

“We worked with a dialect coach. We found that Ali had a big, wide open chest and that’s what gave him a big resonant voice, but he also really constricted his throat which gave him almost a higher pitched sound and then we traced essentially the flavour of his dialect to Southern Baptist preachers.

“You know how he’ll get really low and speak really low and getting really dramatic, and then he takes it up high so it’s really that very holy Baptist preacher trying to impart the holy ghost.”

If it ever actually comes to pass, what chance does he think Tyson has against Lennox Lewis?

“That’s a tough one. That’s real tough. If Mike trains, he’s hard to beat. But I think Lennox Lewis is a heavy enough puncher and a cautious enough fighter to potentially beat Mike cause he’s jab, jab, jab, right hand and will tire him out. I think if he gets past the third round he will be a really great champ.”