In many ways, 2008 has been Kings of Leon’s year. The four-piece from Tennessee, have, over five years, slowly but surely built their way up from a healthy cult-following to the arena mega-league. While the White Stripes and the Strokes, those US “heritage rockers” who emerged around the same time, have failed to capitalise on their early success, Kings of Leon have gone from strength to strength.

Their fifth album, Only By the Night, went to No 1 on its release in September, while their June 2009 concert dates, including one at London’s O2, sold out in record time. If Oasis are the average British punter’s favourite home-grown band, Kings of Leon are their favourite American rock act, with the cartoonish quality of a latter-day ZZ Top. Having debuted at No 1 in the US with their album, they could soon be vying with Coldplay and U2 for the title of world’s biggest band.

They have achieved this escalation via such old-fashioned values as hard work, consistency and giving the public what it wants. In so doing, they have appealed to an increasingly broad audience, attracting new converts with each release and tour.

“Converts” is the right word: brothers Caleb, Nathan and Jared Followill (fourth member Matthew Followill is their cousin) are the sons of a travelling United Pentecostal church preacher, while fans express their love for the band with almost religious fervour — one correspondent to the BBC website spoke of a “Biblical performance” after their headline slot at Glastonbury this summer.

But they don’t just appeal to indie anoraks and music buffs with their southern-fried boogie and pop hooks, their epic sound and spacious, ringing production. They have a big female following, drawn to their swagger and charisma, typified by their recent hit single,

Sex On Fire.

They have the double-whammy: a reputation for adhering to rock’s sex-and-drugs credo to the letter, as well as a sense that they’re in touch with their softer, spiritual sides. For women who have outgrown Westlife et al, Kings of Leon are the most credible boy-band on the planet, and for the guys, well, they offer simple rock thrills with a hint of danger. What’s not to like?