Townshend was the driving force of The Who
The Who guitarist Pete Townshend, who has been cautioned by police for accessing a paedophile website, is a founder member of one of the world's most rebellious rock groups.
The band's founder member rarely gives interview and tends to let his music do the talking.
The title of spokesman for a generation - which has dogged Pete Townshend since the earliest days of The Who - has never sat easily on his shoulders.
I imagined the band would last two or three records at the most
Alongside the Beatles and the Rolling Stones, The Who were leading lights in the music of the 1960s and 1970s, with Townshend playing a crucial part as their chief songwriter.
Townshend himself came from a musical family.
Both parents were musicians and the young Townshend, born towards the end of World War Two, attended Acton County Grammar School in west London.
He formed the band with school pals Roger Daltrey and the late John Entwistle - first in 1959 under the name the Detours, then as The High Numbers.
With Keith Moon joining as drummer they became The Who.
It was Townshend's song writing talent that was behind tracks such as My Generation, Substitute and I Can See For Miles, as well as Pinball Wizard from the Who's rock opera Tommy.
They became known as much for their destructive stage shows as for the music. Their live gigs often erupted with the smashing of guitars and amplifiers and Pete was regularly seen jumping and windmilling his guitar violently.
The effect of all this high-volume chaos was to leave the guitarist almost deaf - and suffering some debilitating tinnitus in later life.
Wary of journalists, the guitarist has long abhorred doing interviews, preferring to be heard through his songs.
What came through The Who's music was a pathological mistrust of the establishment, which a young Townshend used to his advantage.
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Townshend once said of his writing: "Although I was well past my teenage troubles, our music was specifically designed to lubricate the passage from adolescence to adulthood."
Those early classics were also something of an albatross around the songwriter's neck.
He feared he would never be able to recapture the brilliance of his early writing.
"I imagined the band would last two or three records at the most," he told this month's Uncut magazine.
The rock opera Tommy grew out of a conceit to create something bolder and more ambitious than simple pop songs. It was a huge success.
In October 1975 The Who released their seventh album, The Who By Numbers.
The songs, However Much I Booze, Dreaming From The Waist and Blue Red and Grey reflected Townshend's personal battles at the time.
As well as his problems with alcohol, he also became hooked on the prescription drug Ativan, and was lucky to survive the experience.
He was also juggling the demands of being a family man.
He had married his long-time girlfriend Karen, and had two children, who are now in their 20s.
In 1980, two years after Moon's death from an overdose, Townshend launched his solo career with his album Empty Glass. Further projects followed.
Townshend planned an even more ambitious rock opera, called Lifehouse, from the 1970s, but the project was dogged with problems.
It has still never been performed live, though songs have been featured on Who albums and on the radio.
Throughout The Who's long Eighties hiatus, Townshend tried solo material but none of his albums were big sellers.
The most interest was for his musical version of Ted Hughes' children's story The Iron Man, which featured three songs performed by a reformed Who.
The band have since reformed and played several reunion tours.
Kenny Jones [second L] stood in for drummer Keith Moon in 1979
But Townshend has recently exhibited the air of a man who has seemed constrained by three-minute pop songs.
But the last few years have also seen this one-time firebrand appear to mellow.
He has started campaigning for several causes.
In May 2000 he auctioned off some of his musical equipment to help raise money for drought and flood victims in Africa.
He also played to raise money for a San Diego theatre the same year.
The man who once vowed - through Roger Daltrey - that he wanted to die before he was old seemed to be approaching a comfortable, thoughtful stage of his career.
January's arrest related to child pornography charges brought the 57-year-old star back into the limelight in the harshest possible way.
Townshend vowed he was innocent, saying to newspapers that he had merely been "stupid" accessing the site, which was, he claimed, research into paedophilia because he thought he had been abused as a child.
Townshend's bandmate Daltrey also rallied to his defence, saying the guitarist had been the victim of a witch hunt.