It is with some trepidation that I walk up Broadway toward my rendezvous with Sean “P.Diddy” Combs, who minutes before I meet him is staring down at me from a 172 ft-high vinyl advertisement towering over Times Square - it is the biggest billboard in America - dressed as a black James Bond, chest filling a white tuxedo, next to a muscular-looking bottle of his modestly named new fragrance I Am King.

It is not just that his PR lady has warned me that P.Diddy can be a bit terse - “bombard him with questions, try to get him going,” she urged. But on the train to New York, as I read up on this hip-hop titan, black icon and King of Bling, I felt a creeping sense of dread as I realised that Sean Combs and I could never be called, shall we say, brothers.

As a skinny Englishman who thrills to the sound of Bing Crosby, I begin to feel rather a square, and very, very white.

I am directed up to the “skylounge” of an exclusive apartment building where Combs has rented a floor of suites. I am interviewer No 40 on press day for his new fragrance. Also waiting are a beautiful African American lady from a hip-hop website, and a nervous woman from AOL, who concedes to being a bit starstruck.

In a bowl sit sample bottles of I Am King. The press release says that it combines “clean notes with sensual fruits and warm skin nuances. I Am King makes the ultimate statement for today's ambitious go-getter: here I am, in all my glory. Smell the power. Feel the success. I Am King empowers the modern man to take on the soul of a king and conquer his biggest dreams”.

I try to squirt some on my neck, but I miscue, sending what feels like an ounce of liquid fire into my left eye. For the next hour, it won't stop weeping.

Finally, I am ushered into the inner sanctum and come face-to-face with Combs, whose career has been a hugely successful journey that has turned him into one of the US's wealthiest African Americans, with an estimated net worth in 2006 of $346 million.

He was Puff Daddy, a music producer and party promoter, who founded Bad Boy entertainment in 1993. He then became P.Diddy, a rapper who helped to turn hip-hop into a mainstream phenomenon courtesy of such acts as The Notorious B.I.G. On his way to dropping the P - “it got between me and my fans” - and becoming, in the US at least, simply Diddy, he has transformed himself into the front man for his own fashion label, Sean John, and is now an actor. He has won three Grammys and his clothing line is sold worldwide. He owns a private jet. He has never married but is the father of five children from two women.

I thrust out my hand like a member of the British Armed Forces. He, in a startlingly beautiful grey three-piece suit, proffers a clenched fist - so we fist-bump. Even through the painful mist that is blurring my vision, I can see a glittering, silver, diamond-encrusted wristwatch.

November 4 was Combs's 39th birthday - and also the day that Barack Obama was voted President-elect. Combs is sitting before me, eating vegetable soup. He had been an enthusiastic supporter of Obama before the election. “You had a lot to celebrate on November 4,” I open up with, trying to make him unterse. “Yes.” Slurp.

So I ask him how he felt when he watched the election night results - and suddenly we are off. “Oh, man, I mean words can't explain it, you know, it was such a sense of pride and joy and, you know, emotions and shock, too. I thought I was dreaming. I'm still in shock, still in shock. I get prouder every day to see him speak, and just tell the truth, tell us how it is. It's going to be hard, it's not going to be easy, we've all got to work together and not let the whole Democrat Republican thing stand in the way. I'm just inspired.”

Combs believes that if a black man can enter the Oval Office, then a black man can become James Bond. And that man is him. The PR lady had flagged this up before the interview and he has clearly given this a lot of thought. “Yeah, I mean, it's about time. You know, white people aren't the only people who have to save the world, or be president. You know, I think that James Bond from London should be sent on a mission to come to New York and he should meet me, black Bond” - I laugh, and then stop - “he should get kidnapped, and I should have to save HIS ass”.

Combs said he had not put the proposal to the Bond people yet, but he had put the idea “into the atmosphere”. They are always looking for new plots, I suggest.

“Yeah, they need a new swagger. Or just somebody to help accentuate the swagger that's already there because I love the Bond that's there now.” You like Daniel Craig? “Yeah, I don't want to take his job. But he should just know that he has a counterpart in the United States.”

I remind Combs that he recently said that when people see Obama, they see a strong and elegant black man. Is that the way he views himself? He points to a picture of him in the white tux, the same one looming over Times Square. “Yeah, I mean that's the way I view the images.” He adds: “That picture will rival any Ralph Lauren ad in sophistication, in elegance.” He mentions his original rapper look - “baggy jeans, the jewels dripping” - and says: “Not saying we lose that, but it's also good to see a balance of imagery.”

Obama has said he loves rap, but has been critical of the baggy trousers, the vulgarity, the misogyny and materialism in so much of the lyrics. Does Combs agree?

“I don't agree with the pull-up-the-trouser thing. You know, I'm not going to dictate how nobody dresses.” But he agrees with Obama that black men should be responsible fathers. “That's what I Am King is all about. We are all the descendants of kings. It's about empowerment, it's about leadership, it's about a celebration of men. Especially in these hard times.”

Is he worried about sales of a fragrance that sells for a princely $57 a bottle?

“That's the recession price,” he fires back. “This is not like the junk you get in like a corner drugstore. This is Sean Combs and Estée Lauder. This is the best juice you can wear on your body.”

I can't get out of my head the sheer scale of Combs dominating Times Square on that 172ft canvas. I ask him how it makes him feel being on the biggest billboard in America. “It's great for my ego,” he laughs. “Naaah, it makes me feel proud, you know I'm sayin' that people from all over the world come into Times Square and see an image that's a positive image of black power.”

What does Obama's win mean for African Americans in the US? “I think what it has done, it has given us a sense of belief, and empowerment, and almost like it's raised our self-esteem, which is something we needed, and I think it healed a lot of wounds.”

In what way? “I mean, you know, we were brought over here as slaves and hosed down and lynched and all that wasn't like, that wasn't like hundreds of years ago. So those wounds are still open, you know what I'm sayin'? But [Obama's victory] was a step in the right direction.”

In 2004, Combs ran a campaign called Vote or Die, to get young people to the polls. Never one to doubt his own role in history, he now credits his efforts four years ago in playing a part in Obama's win. He points out that about 80 per cent of hip-hop buyers are white, and that “through hip-hop everyone could communicate online and that was his base, the hip-hop MTV generation community”.

He adds: “I wasn't surprised that [John] Kerry lost. I didn't think he was delivering the message that was going to ignite the revolution. I think Obama did that. My role was to plant the seed and start the process in educating the voters. My dream came true. I'll go down in history as like, you know, as one of the people that really believed in the youth vote instead of criticising it and I think they showed up for Obama.”

Combs was born in the public housing projects of Harlem. When he was 2, his father was shot to death in his car after a party. His mother moved them to the middle-class New York neighbourhood of Mount Vernon, where he went to private school. He went to Howard University in Washington, where he showed his penchant for party - and self - promotion. He dropped out to get into the record and nightclub business, and there is no doubt he has worked enormously hard.

Next year he is bringing out an album; February 13 sees the UK release of Notorious, about the life and murder of Christopher Wallace - the rapper The Notorious B.I.G, aka Biggie Smalls and Big Poppa - who with Combs helped to put East Coast, New York rap on the map at a time when it was dominated by the West Coast, Los Angeles artists. It was quite a rivalry. Biggie was killed during a drive-by shooting in Los Angeles in March 1997 six months after his arch West Coast rap rival, Tupac Shakur, was killed in a drive-by shooting in Las Vegas. Combs has always fiercely denied any involvement.

Combs has had his trying times - nine people died in a stampede at a concert he organised in 1991 - and he was acquitted of bribery and illegal gun possession after shots broke out in a New York nightclub in December 1997 while he and his former girlfriend Jennifer Lopez were inside.

A large element of hip-hop has focused on street violence and black victimhood. Will it change now that a black man will inhabit the White House? “Hip-hop has always been a reflection of what's going on in society so it may have more of a positive tone, more of a sense of pride, yeah, just more celebratory, more hopeful, more proud, more confident.”

Someone in the room starts making slashing gestures across their neck. After 16 minutes, our time is up. Combs berates Hampton, his publicity man, because we haven't spent enough time on I Am King.

I am sure the fragrance will do just fine. What was most striking was just how moving and uplifting and, yes, empowering, Obama's victory had been for a multimillionaire black man with the self-belief of Combs. Imagine how those elderly Civil Rights survivors felt on election night down in Alabama.

Sean John I Am King fragrance is sold exclusively at Debenhams. Notorious is in UK cinemas from February 13.

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