Vivienne Westwood: Disgracefully yours, the Queen Mother of Fashion

Once she shocked by mocking the Queen. Now she's done it with her choice of models

From high priestess of punk to Queen Mother of British Fashion, Vivienne Westwood has undergone a series of remarkable metamorphoses in the past 25 years. Like Quentin Crisp, Boy George and Elton John, she is a national treasure that time has rendered respectable. But at 61, age has not withered her talent to abuse her status as beloved (and indulged) English eccentric. Last week the godmother of sedition struck again when she unveiled the final-year collections by her students at the Berlin University of Art fashion department. The designs were modelled by inmates of an old people's home. "Life becomes richer as you grow old," she declared. "I like the ageing process and have no problem with it."

The oldest ingénue in the fashion business, Westwood is growing old disgracefully. Today her determination not to be cowed by age is a mark of her innovation. Her longevity has granted her artistic licence to shock and still belong. As she says: "I may be a rebel but I'm not an outsider." Twenty-five years ago she was just as challenging, marking the Silver Jubilee by sticking pins through Her Majesty's nose on T-shirts designed for Malcolm McLaren's punk prodigies, The Sex Pistols.

No one would affect more bemusement than her that in a fortnight, Sotheby's is auctioning a T-shirt designed in the 1970s by Westwood and McLaren, her co-conspirator and former husband. Bearing the legend "Don't **** your Mother", it carries an estimate of £400-£600.

How a suburban primary school teacher became the woman who today encourages her students to put old people in hot pants is worthy of Pirandello's pen. Born in Glossop, Derbyshire, in 1941, Vivienne Swire had an upbringing remarkable only for its ordinariness. Her father worked first in the Wall's sausage factory, then ran a sub-post office in Harrow, in north-west London. Despite the early move to the South she retains a thick Northern accent one interviewer called "as sweet and gormless as a lollypop lady's". It was at a dance in Harrow that she met her first husband, Hoover factory apprentice Derek Westwood, in 1961. The white church wedding took place on 21 July 1962, and Vivienne made her own dress. Her son Benjamin was born in 1963, and she worked as a suburban primary school teacher in Willesden, north-east London.

The end of her marriage came when she met Malcolm Edwards, the man who was to change his name to McLaren and become her Svengali. It was he who persuaded Westwood to cut her long brown hair, bleach it blond and invent the subversive punk spike hairdo before Bowie popularised the look as Ziggy Stardust.

Punk was really McLaren's gig. Their first shop, Let it Rock at Paradise Garden, opened on the King's Road in 1971 and from there Westwood sold the customised Teddy Boy threads that developed into punk. The collaboration with McLaren progressed to further punk boutiques and produced a son, Joseph Corre. Of the punk years, Westwood said: "It changed the way people looked. I was messianic about punk, seeing if one could put a spoke in the system in some way. I realised there was no subversion without ideas. It's not enough to want to destroy everything."

Westwood claims she didn't consider herself a fashion designer until punk gave way to new romanticism and she designed the Pirates collection in 1981. Then began her exploration of techniques that led the Women's Wear Daily publisher John Fairchild to name her one of the six most influential designers of the 20th century. The Pirates collection was the beginning of her intellectual journey into the history of costume. Tailoring techniques from the 17th- and 18th-centuries were studied, then subverted. She paved the way for the next generation – John Galliano and Alexander McQueen – to reinterpret fashion history. She created a new language of clothes. Her signature corsets celebrated the silhouette of 18th-century courtesans. She took the crinoline and re-cut it as the "mini crini". Tweed and tartan were made into suiting echoing medieval armour. The fashion historian Jane Mulvagh, who wrote Vivienne Westwood: An Unfashionable Life, says of her clothes: "[They] provide an ironic mask with which she can project many personae and behind which she can hide her vulnerabilities and even her ordinariness."

While Westwood's choice of references is erudite and conservative, what she chooses to do with them is little short of anarchic. It is between this tension that her talent plays. Her grand demeanour masks the old punk at play. But to dismiss her clothes as risible is to underestimate her talent. She works magic with the female form and she understands the old stripper's adage: "Make them beg for more, then don't give it to them". Her women are like fin-de-siècle Parisian cocottes teetering on those sky-high platform shoes Naomi Campbell fell from on the runway.

Far from disempowering women by lacing them back into the corset and reintroducing hobble skirts and mini crinis, Westwood liberated a feminine power not seen since Madame de Pompadour's glory days. To her credit, she simply chose to rise above 1990s minimal fashion, and carry on regardless. She shares the self-belief of Margaret Thatcher, whom shedressed as for a Tatler cover. Though Thatcher never wore Westwood, she was a great admirer of the lady's work when modelled by the former Conservative Party treasurer Lord McAlpine's ex-wife Romilly. That piece of punk to be sold at Sotheby's is part of Lady McAlpine's collection of Westwood. Anyone who could claim Westwood's work is a joke will be cowed by estimates that soar as high as £2,500 for glorious pieces from the great collections "Dressing Up", "Anglomania" and "Grand Hotel", "Café Society", "Vive La Cocotte" and "Storm in a Teacup".

Westwood today is a mass of contradictions. She stands outside fashion, and unkinder critics say she's been showing variations on the same collection for the past 10 years. This should not detract from the astounding body of work she has produced, nor the dedicated following she has amassed. She still owns the empire she has built and even turns a profit on her couture Gold label. She hops from one idea to another with her mind often working faster than her Northern brogue can accommodate. She is often shocked to her suburban roots that people laugh at what she takes so seriously: her clothing and herself.

Though Westwood may rail against the philistines in fashion, the death of culture and the shallowness of the schmutter business, she is a much-loved mother to the young British designers currently setting the world on fire. She may be easy about her own old age, but she still connects with a younger generation. In 1992 she married again, to Andreas Kronthaler, 25 years her junior.

The irony may be lost on her that she is a beacon of the culture that she dismisses as dead. As TS Eliot said: "Culture may even be described simply as that which makes life worth living." In this estimation, Westwood's clothes – and the woman herself – are guilty as charged.