He’s gone from the Sexiest Man Alive to one half of the World’s Most Talked About Couple. Yet these days, with a gritty role in Inglourious Basterds and high-profile charity projects, Brad Pitt casts himself as the cultured philanthrope. But is it a role that suits him?

Brad Pitt is nursing a hangover. He rubs his bleary blue eyes, reaches for a jug of orange, and pours himself a tumbler, gulping it down in one go. There are a few lines around the eyes these days, and the snake-hipped young man with faded denims and a cowboy hat in Thelma & Louise is now a mature 45-year-old. But today, dressed in dark slacks and a blue shirt, and despite the sore head, he looks as ludicrously handsome as ever.

“Late night,” he admits before settling down in an armchair in the corner of a boutique hotel on the Riviera. “Now, I need coffee.”

The “late night” started with Pitt and his partner Angelina Jolie making what seems an annual pilgrimage to the red carpet at Cannes. Last year it was a protective Pitt shepherding a heavily pregnant Jolie (who two months later gave birth to twins Knox and Vivienne).

This year it’s her turn to show up for him. Pitt plays the lead in Quentin Tarantino’s Inglourious Basterds, which thanks to the director’s trademark mix of black humour and graphic violence stirs up its fair share of controversy among the critics. It’s nothing, of course, compared with the column miles reserved for Pitt and Jolie – their public show of affection interpreted, in part, as a bid to quell the speculation surrounding their relationship.

“Split latest!” was the front page on one British glossy. “Now it’s war!” screamed a US magazine. “Yeah, we’re really miserable,” Pitt deadpans but conveniently doesn’t answer the question directly. Later, he insists the red carpet appearance wasn’t simply a PR exercise. “No, no. It’s fun up there and I love it. We’re not even really aware of what is going on.”

That, frankly, is hard to believe. Likeable though Pitt is – and those who work with him consistently tell the same story, that of a decent, generous and kind man, a down-to-earth guy and talented actor who tries his best to retain some grip on reality in the midst of the media-induced madness – he presumably has access to the internet, is clearly not illiterate or living a life of monastic recluse. The Brad and Angelina show is now a soap opera of global proportions, and while most of the stories are simply too libellous or too ludicrous to recount here, they make millions for the celebrity weekly market.

Common themes in recent “stories” are: Pitt is unhappy and has been calling his former wife, Jennifer Aniston. Jolie is fed up with Pitt’s drinking and Pitt is only drinking because he is unhappy. Jolie has quit the family home on the twins’ first birthday and moved into a hotel.

Today, Pitt is wary and guarded, although at all times, unfailingly polite. He’s clearly weary of discussing the one area that lurks, like the proverbial elephant in the room, around any journalistic encounter with him. “We just don’t really participate,” he says of the phenomenon that surrounds them. “It kind of goes on without us. It’s self-generating. When I was younger I would take it personally; it was such an injustice to me. As a man or as a woman I don’t know how they could sit there and do it. I mean, [the stories] are consciously fabricated and I don’t know how you could do that.”

What is true is that Pitt had been married to America’s favourite Friend Aniston for five years when, in 2004, he was cast opposite Jolie in the high-octane thriller Mr and Mrs Smith. The chemistry palpable on screen clearly spilled over into real life and within months Pitt’s fairytale marriage was over (they divorced in 2005) and what’s now become known as the Brangelina phenomenon began.

Pitt and Jolie aren’t yet married, although last year Jolie commented, “I’m sure one day we’ll do it. We’ve both been married before and it’s not about some piece of paper. Maybe we’ll do it when the kids start asking.”

Worlds apart

Certainly, Jolie’s unconventional lifestyle, the stories of blood-swapping marriage ceremonies and bisexual relationships, is a world apart from Pitt’s milk-and-cookies start in life. With his brother, Doug, and sister, Julie, Pitt was raised in Missouri in a secure, middle-class, Southern Baptist family – his mother, Jane, was a high-school counsellor and his father, William, ran a truck company. The image of the regular guy, happiest hanging with his mates, beer in hand, still seems the better fit for Pitt than the one he now lives escorting the most exotically beautiful woman to premieres or UN field missions, hopping from one country to the next (Pakistan, Haiti, Somalia, the list is endless).

The couple seem constantly to be on the move – there are homes in California, the South of France, New Orleans and, apparently, Cambodia, where Jolie adopted their eldest son, Maddox. They take it in turns to work, and when one is on set, the other is at home with the kids, and that, too, means they are often in a different city – Berlin for Inglourious Basterds, New York for Jolie’s next thriller, Salt. Jolie was on the move in this way pre-Pitt, and it seems to be her lifestyle that takes precedence.

Even with the entourage of helpers that money can provide, it sounds exhausting. Pitt insists that they love it: “Everywhere is interesting in its own way, each place has its own feel and something to offer: you pick up something, the kids are picking up something. They have this world view which we are very proud and happy that we are able to provide.”

He claims they don’t read any of the gossip, but lets slip that when the kids – Maddox, 7, Pax, 5, Zahara, 4, Shiloh, 3, and the 1-year-old twins – see pictures of Mom and Dad in magazines, they have to try to explain that their parents are a little different from others.

“We’re still trying to negotiate how we explain to them what we do. It’s not strange to them that their parents will come on television. And it’s not strange for them to walk outside and for there to be a photographer. They just think if there is printed material [as he disdainfully refers to the gossip mags] hanging around, their parents might be on the cover.”

Surely they must be tempted to take a peek? “No, there’s no point.” You do wonder how they can ever get away from it and live some semblance of a normal, family life.

“Oh, we get peace in our lives. We got out here a couple of days early with the family and we get to hang out in a place in Provence. We’re pretty good at it. You carve out that time for the family. Do we get a little silence with the kids? No, not that kind of silence – silence is over at home, but we like that chaos?”

It’s certainly a long way from Kickapoo High School in Springfield, Missouri, where Pitt excelled at golf, tennis and swimming.

Pre fame, he worked as a driver (legend has it that most of his clients were strippers), lugged fridges and even dressed up as a giant chicken to promote a fast food joint. It adds up to the image of a great-looking guy out to have a good time as he made his way in the world.

There are still glimpses of that laddish side to him. Ask him an innocuous question about filming in Berlin, where Inglourious Basterds was shot, and he fires back: “Berlin is not a stranger to us. I like the beer, as you can see from this morning. The beer is good.” Tarantino sold him the idea of playing Lt Aldo Raine in Inglourious Basterds over a boozy dinner at the actor’s place in Provence. “The next morning I woke up to find a load of empty wine bottles and the realisation that I’d agreed to be in his movie,” Pitt jokes, going on to tell a risqué story about the film set including a rather gross-out practical joke involving a purple dildo.

The cheeky camaraderie and good ol’ boys humour seems to come so naturally that one wonders whether the cultured, philanthropic Pitt is all a bit of an effort for him, as he turns himself into the worthy global citizen his other half desires. He can be inarticulate when asked to analyse his work. Probe about films he watched in preparation for Tarantino’s Second World War “fantasy” and there’s a long pause.

“When you get into a Tarantino film he has all the back story lined up for you. It’s all teed off and it’s really well thought out. Other films? Let me think. That requires memory and I’m struggling with that right now.”

Best to let the work do the talking for him. When he’s on screen, it’s easy to be blinded by those good looks – especially in the films that do their best to showcase him as a heart-throb (A River Runs Through It, Troy) but there are plenty of others (Fight Club, The Assassination of Jesse James and, indeed, Inglourious Basterds) that prove that Pitt is a skilled actor.

Ask about his projects away from acting and, while he becomes more animated, there is a slightly rambling quality to what he says. He has none of his friend George Clooney’s knowingness or political sophistication. “It’s going really well,” he says about Make It Right, the affordable housing project he launched to help build New Orleans’ impoverished Lower Ninth Ward, one of the neighbourhoods worst hit by 2005’s Hurricane Katrina. “By the end of the year we will have 100 homes and it will be the greenest, most intelligently designed neighbourhood in the United States. We have families coming in and their electric bills are $8, $12. It’s a big deal for anyone, but for a low-income family, it’s life-changing. It’s also a big deal because it’s proving technology at all strata. It’s amazing and I thank everyone who’s been involved.”

There is no doubt of his sincerity on these issues, though, and from Jolie he’s learnt that while the dark side of celebrity is being stalked by photographers and subjected to endless speculation, there are positives, too, the main one being the power to do some good. And sometimes one can finance the other.

If the celebrity magazines were desperate for pictures of the newborn twins, now one year old, why not get the best price for them and put the money to some use? When snaps of Knox and Vivienne were sold for a staggering $14 million, it was followed by a philanthropic spree. Via their Jolie-Pitt Foundation they gave $1 million to displaced people in Pakistan, and another $1 million to set up the Jane Pitt Pediatric Centre, named after his mother, in his home town. They have poured cash into aid programmes for Chad and Darfur, supported Doctors Without Borders, and many more. Indeed, according to their tax records, they donated $8 million to charity in 2006 alone – long before the baby photographs deal.

Despite Pitt’s down-to-earth image, his film choices have tended to the unconventional. He may have burst on to the scene when Ridley Scott cast him as the pretty boy drifter in Thelma & Louise, but since then he has side-stepped the obvious, pin-up roles. His career is defined by interesting choices – playing a stoner in True Romance, the crazed son of a scientist in Twelve Monkeys – and even when he has gone for the mainstream, he likes directors who are quirkier, such as the Coen Brothers (Burn After Reading) and darker, such as David Fincher who cast him in Se7en and The Curious Case of Benjamin Button. His next project, The Tree of Life, is with the reclusive director Terrence Malick.

“Listen, I like a bit of extreme and I’m always looking for other areas and pushing in different directions, but it’s kind of incumbent on what comes your way to pick from.”

Tarantino was a perfect match, he says, and Pitt is excellent as a tough-as-teak officer, Lt Aldo Raine, who recruits a crack team of Jewish American soldiers to operate behind enemy lines and strike fear into the Nazis.

In the future, Pitt hints that acting will have to take its place in the queue along with the other passions – the family, his charitable work and producing. His company, Plan B Entertainment, has an impressive track record with The Departed, Charlie and the Chocolate Factory, A Mighty Heart and The Private Lives of Pippa Lee. “I think [acting] is a younger man’s game; there are fewer interesting parts for older people and we all get older. But I feel like I’ve done it. I’ve kind of had my time and that’s quite freeing.” It’s the sort of line you expect from a 60-year-old, not someone who’s 45, an age when leading men in Hollywood often do their best, Oscar-winning work. And surely winning that elusive Academy Award would be the ultimate way to prove to Angelina that he’s more than just a regular guy. Are there any acting dreams left for him?

“Yes, of course there are,” he smiles. “But I’ll do them first and then we’ll talk about them.”