Charlie Hunnam: The Queer As Folk star has grown into a burly biker with a top-rated cable show

Charlie Hunnam knew what he was letting himself in for. It was all there in the script. Within minutes of appearing on a TV screen in his first major role, playing a 15-year-old schoolboy, he'd be having his naked bum licked by a drug-taking club Lothario. "I was just thrown into this world and it was all so exciting, and I didn't really have any gauge of what was a normal day on a set and what wasn't," the actor says of his appearance in Channel 4's headline-rattling 1999 drama Queer as Folk. "But I was a pretty fearless kid. I was just amazed that I'd been given this opportunity. I jumped in head first."

Did getting his kit off, sticking his legs behind his ears and pretending to prematurely ejaculate on another actor's chest come easily? "I wouldn't say it came easily," laughs Hunnam, who turned 30 this month. "But easier than it would now!"

Newcastle-born Hunnam was 18 when Russell T Davies – more recently Doctor Who's reboot Svengali – cast him as young Nathan in the writer/creator's ground-breaking series set amid Manchester's vibrant gay community. The voiceover at the beginning of the first episode described Hunnam's character as "the one-night stand that never went away". Beautiful, blond, inexperienced Nathan was the youngster who bewitched sharp-suited gadabout Stuart (played by Aidan Gillen) and nice, soppy Doctor Who fan and narrator Vince (Craig Kelly).

Off-screen, too, Hunnam was causing a fuss. As the show's critical applause – and the controversy over its near-the-knuckle depictions of gay sex – reverberated, the teenage newcomer received many a tempting offer. Queer as Folk was recommissioned for two specials. Hunnam was invited to Hollywood to meet managers and agents. And Madonna asked him over for dinner. Come again?

"She told me not to tell the cab driver whose house I was going to," he remembers of the ride to the star's Beverly Hills home. Hunnam was so paranoid that he exited the taxi at the bottom of her street – not realising it was "a mile long". He arrived late, sweaty and clutching his dinner gift: a Wonder Woman Pez dispenser. ("Well, what wine would you take to Madonna for dinner?") Inside, a crew of dinner guests were waiting for the teenage Geordie, including Sandra Bernhard and the actress Debbie Mazar ("Debbie Mazar! From Goodfellas!"). Someone asked him why he was in town. "For a job," he replied. "A blow job?" Madonna asked, to much laughter. Hunnam groaned. It was going to be that kind of dinner. Fame had come walloping into his life, and he wasn't sure he liked it.

Charlie Hunnam didn't know what he was letting himself in for. He signed on for the lead role in Sons of Anarchy, a new American TV drama about biker gangs in northern California, knowing that the material was lyrical, intense and violent. Certainly he understood that, to play a gun-running gang's violent-but-idealistic vice-president Jax, he would have to research the codes and nefarious activities of the Hells Angels and their outlaw associates. He'd need to learn how to ride a Harley-Davidson, get (fake) tattoos, grow his hair and stubble, and put in serious gym time. He knew that American cable network FX – the "edgy" outpost of the Fox empire – was right behind the show, which was created by Kurt Sutter, previously an executive producer on dark, tough cop show The Shield. But he didn't grasp how successful it would be, nor how far it might take him.

Critically acclaimed, in its second season – which starts here on Bravo on Wednesday – Sons of Anarchy was the highest-rated cable show on American TV last year. Season three begins shooting in Los Angeles next week.

"The show is obviously larger than life," Hunnam says of a series that is part Sopranos (crime family operating as quasi-normal family) and part Shakespeare (the Hamlet-like Jax's dead father founded the Sons of Anarchy gang; his iron-willed mother is now married to the club's vicious president). "There is almost a graphic novel approach to this world. But the thing that grounds it is Kurt's attention to detail," he adds. Sutter, a tattooed, imposing figure who plays an imprisoned gang member in the show, spent time getting to know biker gangs in northern California. "The details – the right bikes, the right clothes – give us licence to tell very big stories."

Eleven years since he relocated to LA to pursue his acting career, the Queer as Folk kid, who largely disappeared from UK screens for almost a decade, is back, and he's joining the likes of Hugh Laurie (House) and Dominic West (The Wire) in the ranks of Brit actors heading up quality American TV drama. Earlier this month, he was in New York with FX president John Landgraf. Exec told actor: "Get ready, cos you're gonna be doing this show for another five or six years."

The success comes after years of "having my heart broken on other jobs" (among many other disappointments, he lost out to Russell Crowe in Ridley Scott's A Good Year), and at one point not earning "a single dollar" for 27 months. Hunnam's story – candidly, unaffectedly told in an accent that quickly slides back into a north-east burr Sting would kill for – is one of rejection, stubbornness, sticking to his guns, a failed marriage, and Brad Pitt saving the day.

Hunnam says he is up for fulfilling the seven-year Sons of Anarchy contract he's "written in blood... You know, I'm a little bit of a gypsy at heart, so the idea of being tied to one thing for a long time causes a little bit of anxiety. But I love the show. And I love all the guys. As long as we keep moving forward, and it doesn't get stagnant or derivate, I'll be keen."

It's a bright spring morning in Hollywood, and grungy Charlie Hunnam is lolloping around his modest backyard, smoking full-fat Camel cigarettes. The small swimming pool has a solid wooden beam over it. For his role in Anthony Minghella's Cold Mountain, he had to do a backflip; he practised jumping off this beam into the pool. This was also the hang-out for Hunnam and his old crew of friends, Seth Rogen, Jay Baruchel and Jason Segel. The "backyard Olympics" tomfoolery that featured at the beginning of Judd Apatow's hit comedy Knocked Up began life as poolside larks at Hunnam's place. He and the three American actors (all of whom were in Knocked Up) had appeared in Apatow's short-lived 2001 sitcom Undeclared. "For the first episode of that I got paid twice what I got for all of Queer as Folk," says Hunnam. He's not boasting, just marvelling – still – at the ludicrous money that sloshes around Hollywood. '

He bought this house around 2002. In an 18-month period, he filmed Cold Mountain, the lead in a big-screen version of Dickens' Nicholas Nickleby, Undeclared and a film called Abandon. "It's crass to talk about money, but I had a load of money in the bank. So I thought, 'Do the smart thing,' and I bought this place."

But equally, there were "giant periods of time" when he couldn't pay his mortgage while simultaneously turning down two "million-dollar offers". They were both horror films, one starring Christina Ricci, written by Dawson's Creek creator Kevin Williamson, and produced by Bob Weinstein. "I was to be a wolf guy," he says, wrinkling his nose. "I remember being in the room with Bob. I was like, 'Listen, I'm really flattered and I appreciate how much you want to work with me...' He goes, 'OK, 750.' 'It's not about the money, honestly.' 'OK, 850.' 'Listen, that money would absolutely change my life but I can't do it. I don't believe in this project.'

"Then I'd come home and bang my head off the wall and think, 'What the fuck am I doing? What if my career doesn't turn out the way I want and I've just thrown away all this money and don't have the career I want?' There were definitely some moments of soul-searching through all of that."

Russell T Davies remembers Hunnam's unusual levels of focus from the minute he met him. Faced with the demands of his Queer as Folk script, "Charlie was young and brave and never even blinked... The minute he walked through the door we just thought, 'Well, he's obviously beautiful – let's hope he can act.' Then we asked who his favourite actor was. He said Christopher Walken – which was the most interesting reply we'd had."

Hunnam was first talent-spotted – as a model – while attending The Clothes Show Live in Birmingham. He was later approached in a Newcastle branch of JD Sports by a production manager on Byker Grove. After three episodes of the kids' drama, he auditioned for Queer as Folk. But, says Davies, even though he was still receiving lucrative modelling offers, "he turned them down so he could sit in acting class".

Hunnam's confidence and drive come, it seems, from his dad."He's a real serious guy from Newcastle," he says. "He was a scrap-metal merchant, and before that he was involved in security for clubs at the high end. He's not particularly big. But before I was born he was much, much bigger, big as a house. You know what that scrap-metal world is like – there's some hard boys."

Hunnam's parents separated when he was young, "so I didn't grow up with him. But I grew up aware of how to be in certain situations. And that definitely afforded me a lot of opportunities to continue being invited into these worlds."

When he was filming football-hooligan drama Green Street (2005), he researched his thuggish role with West Ham's "firm" – gangs of supporters that tussle with other clubs' fans – "and they embraced me with open arms. And on Sons of Anarchy, when I'd hang out with these biker gangs, I'd just observe and be very quiet and very respectful. And the more confident these guys felt with me, the more they would open up to me."

There is a photograph of Hunnam, his brother and their dad on his kitchen wall. Hunnam Sr is white-haired, tattooed and, yes, radiates hefty presence. The chunky Rolex on his wrist speaks of the "lot of money" he made as "a big player" on the Newcastle shipyards after leaving the scrap-metal business. "I'm gonna write a film about him one day. As much as he'll let me show, I'll show. It's not my place to go into too many stories about him. But trust me when I tell you he's about as serious as men get," he says with some pride. "He's a naughty fucking boy."

Writing is the other passion in Hunnam's life. While filming Cold Mountain in Romania, he became intrigued by the story of Vlad the Impaler. He spent 18 months researching and writing a historically accurate script based on the life of the medieval nobleman who inspired Bram Stoker's Dracula. Along the way, he rejected several acting jobs from his agent. "I needed to do something that made me feel I had some control over my life, cos I felt like I was spiralling."

By the time he had finished his first draft, Hunnam was so impoverished that he had to sell it fast – he couldn't even afford the time to take up an offer from legendary screenwriter Robert Towne (Chinatown) to read it over and offer notes.

Towne is his former father-in-law: shortly after arriving in the US as a 19-year-old, Hunnam met Katharine Towne. Four weeks into their relationship, they were wed in Las Vegas. The marriage lasted three years, the couple divorcing in 2002. "Yep, three, horrible, tumultuous, violent years," he says, laughing. "She was beating me up!" he jokes (I think). "We were really good friends and remain really good friends. And I'm still close with all of her family. But we were just horrible partners." His current girlfriend is not, as internet rumour has it, Liv Tyler (although they have just made a film, The Ledge, together). He's been dating Morgana, a jewellery designer, for four years.

Anyway, the Vlad script – "It sold so quickly," he says with still palpable relief. The buyer was Brad Pitt's production company, Plan B Entertainment. Pitt, he says, has been a big champion of Vlad, placing strategic phone calls to move along the typically tortuous production process. Hunnam is confident that it will be filmed this year. He'd like to act in it, "but I don't think I'll be Vlad. I'm not a big-enough name to justify the size of budget required. We need a movie star."

Charlie Hunnam never wanted to be a movie star. He wanted to make good choices, take the right parts. Even as a wide-eyed teenager, says Russell T Davies, he was clearly dedicated. "His life was going mad, getting asked to dinner by Madonna and all that. He was only a teenager, but he knew it was a long game and not about posters on walls and having your photo taken."

Shortly after our meeting, Hunnam is off to prepare for the beginning of the five-and-a-half month shoot on series three of Sons of Anarchy. He is undertaking a 1,000-mile round trip to a biker rally in Arizona. And he has, at last, some money in his pocket. "I just got a nice pay rise for the third season. Finally, I can afford to live on this wage," he says with a laugh. "I've always worked for free my whole career. I've never really gone for the money. If it's a question of getting a lot of money in my pocket and there not being enough money to shoot the show properly, I'd rather we do it the way we're doing it. I feel very young, and I've got years to make money. I'd rather make a show we can be proud of than drive a Range Rover."

In any case, he has a shiny Harley-Davidson Dyna in his garage. It is, of course, the real biker-gang deal.

The second series of 'Sons of Anarchy' begins at 10pm on Wednesday on Bravo