"The last record was more whiskey, and this one's more wine," says lead singer Caleb Followill of the hairy quartet's second album release, Aha Shake Heartbreak.

Unlike many of their contemporaries, Kings Of Leon seem to be maturing into a superior vintage of the music world. Along with The Strokes and the White Stripes, they burst into our consciousness as part of an American guitar music invasion of 2002 - which saw almost any band from across the Atlantic elevated to instant stardom.

They then quickly shifted a spectacular half a million copies of their 2003 debut album Youth And Young Manhood.

Yet after the furore surrounding the American guitar music invasion had died down - and Brit bands like Franz Ferdinand and The Libertines had countered with a Brit invasion - the Followills clan (three brothers and a cousin) kept storming on to bigger venues (they're playing the Brighton Centre on Thursday, compared to the Dome last October), gaining higher-profile magazine spots and fiercer praise along the way.

The reason for this continuing zoom towards bigger things seems to be simply that the boys have matured, both musically and in terms of actual years and life experience. Caleb, 23, Nathan, 25, Jared, 18 and cousin Matthew, 20, have developed from sheltered sons of an evangelist preacher into hot-blooded rock 'n' rollers who like a little sex and drugs to spice things up.

"We've kind of grown up between these two albums," says Caleb. "Not in a bad way, not getting old, but there's a lot of growth in this album. I guess it is also a kind of hangover record. We partied hard in London, had a good time."

The genesis of the Kings Of Leon is a strange, gothic American story that tells of naive beginnings for the rocky collective.

Except for a five-year stretch when they settled in Jackson, Tennessee, the three brothers grew up touring the Southern States' revival-meeting circuit in the back of their father's Pontiac, stopping at various spots for a week or two wherever he was scheduled to preach.

They existed like nomads, living in relatives' homes, the back of their car, travel trailers, hotels, parsonages, and pastors' houses, and were either hometaught or enrolled in small parochial schools. They also attended services and occasionally found themselves banging on drums or performing in church choirs.

"We would just stay in churches or hotels," recalls Caleb. "To us it was completely normal. We didn't know it any other way. That's the way it had been since we were like really young.

"Everybody gets real drawn in by the story. Back then we wouldn't have understood why anybody would have thought we were any different, but looking back, it's definitely a weird thing. It was a really strict religion. But if we weren't in music, I doubt anybody would really think it was that interesting."

Despite the KOL boys' insistence that they didn't initially see anything peculiar about their past, there have been allegations that they made the story of their upbringing up to add a publicity-friendly spin to their tale. Some have suggested that the band invented the whole bizarre history of their preacher dad who was eventually defrocked for drinking.

"Perhaps unsurprisingly, the local newspaper in their hometown of Millington, Tennessee, had no record of a defrocked preacher called Followill," wrote Alexis Petridis in The Guardian.

Caleb laughs off such accusations. "If we were going to make something up we would have come up with something a bit more rock 'n' roll, a bit more weird," he says.

The boys also deny papa Followill was defrocked, saying he left the ministry of his own accord after he split from their mother - with divorce being such a taboo in their religious community, he decided it was time to move on.

Whatever the truth of the matter, the changes led to a new, more decadent chapter in his sons' lives.

"Our parents' divorce shattered the whole mirage of this perfect little existence the outside world couldn't touch and couldn't pollute," recalls drummer Nathan. "We realized that our dad, the greatest man we ever knew, in our eyes, was only human. And so are we.

"People are gonna f*** up. They're gonna experiment with drugs, have premarital sex. This whole new world was open to us."

The boys discovered popular culture and devoured it - gluing themselves to the TV and buying every CD they could find. But it wasn't long before they moved on to something more rebellious.

"It took about a year before we were just like completely disgusted with pop culture in general," says Caleb. "We just got really sick of everything that we would see and hear. We kind of would just get pissed off with the way everything was. So we thought we should make music that we could listen to without wanting to throw up.

"So we started thinking about putting a band together. And then the Strokes came out and we started hearing a lot more about the White Stripes.

"It's not that we're influenced by those bands musically, but in the way that they don't care about anything. They don't really care about selling records. I mean they make good music, and they know they do. So they know they don't have to really worry about anything."

And so, alongside such new rock revolution heroes, the Kings Of Leon were launched upon the world.

They soon got themselves a manager and were the subject of a bidding war before signing with RCA in 2002 and quickly banging out a five-song EP followed by their debut album. As their name became known and their rock 'n' roll status established, tabloid tales of drug excess and sexual dalliances with the likes of Kate Moss and Paris Hilton started to circulate.

They were even associated with typical groupie sex scandals. "We're young guys," admits Nathan. "Obviously we're gonna dabble. But you come to realize it has nothing to do with us as people. It's crazy. We'll be telling girls: 'We're leaving in 15 minutes.' And they're like: 'I only need ten.' We're like: 'Are you serious?' And they are."

Their trademark sound combines an adrenalised garage rock thrust with a southern rock twang, which has led some to pigeon-hole them as a hairy bunch of country boys who play the rather old-fashioned rock music of southern America.

"It's easy to see four guys from the south and expect them to make Lynyrd Skynyrd, Allman Brothers type of music," says Caleb. "On the first record we got compared to all these bands, and we couldn't name two songs they had recorded.

"We weren't allowed to listen to bands when we were growing up. So in some ways it was kind of neat to see how similar our music was to music that we had never heard, as a sort of byproduct of where we where raised. I don't think about that much, maybe it came from the fried chicken and biscuits we grew up on."

Their sound had developed by the time they came to make Aha Shake Heartbreak, which which was recorded live with a microphone in the middle of a room, rather than using separate booths. The album drips with confidence which some say comes from the boys' more rock 'n' roll life. It is moodier, more angular, and more distinctly their own than its predecessor.

It also saw them fly back to the top of the UK charts and caught the attention of U2, who asked them to open for them on their tour of America.

"The U2 tour is great," says Caleb. "It kinda freaked us out at first. We did not know what to expect playing in stadiums. It's a totally different sound and we had to play in a totally different way. But now we feel confident playing to 20,000 seat arenas.

"That's the way it goes. We were scared s***less when we started being a band. We didn't have a direction and just played what came out of our instruments. But now we are not scared to try new stuff, and go with what we feel."

Starts 7pm, tickets cost £18.50. Call 01273 647100.