She chose to show in the Grand Salon Opera of the Grand Hotel. It is a magnificent ornate 19th-century banqueting hall, regularly used by couturiers such as Hubert de Givenchy.
Ms Westwood is launching a sustained assault on the world capital of fashion. Before the end of the year she plans to open a shop in Paris, selling her blazers, pin-stripe suits, camouflage-print denim and platform flip-flops. The designer has a mission: to revive the idea of elegance in an inelegant age. In her view, elegance in the Nineties is a subversive rather than conformist concept.
The receptionists at the Grand Hotel had no doubts about that. The designer's followers gathered early in the lobby. It is unlikely that the hotel had ever entertained quite such an extraordinary gathering of people. 'So this,' a concierge said, eyeing a man who looked as if he had been dragged through a hedge backwards several times, 'so this is English fashion.'
Roxy, a friend of the designer who had travelled to Paris from Edinburgh, was a picture of Scottish convention at 20 paces. But then you noticed that the jacket he wore over his kilt and sporran was a Westwood creation: Harris tweed and denim mixed together.
Backstage, the models were trying on some super-elevated nine-inch court shoes. 'They are the highest Vivienne has ever made,' an assistant said proudly. 'We tried putting studs all over them, but they were so heavy, you couldn't pick up your foot.'
Amber Smith, a busty model from Florida, was scheduled to wear a tiny red bikini. 'It snapped the first time I wore it. Maybe I'll just have to hold it in place,' she said.
Naomi Campbell, supermodel, reassured her: 'Don't worry darling. I know what it's like.' She said she would be wearing a G-string in the Chanel show, which took place yesterday.
Anna Piaggi, the Italian fashion eccentric, floated past in layers of brown, including a brown McDonald's waistcoat, the letter M inscribed in yellow on the breast pocket. A dresser spoke in awe: 'She's just a . . . genius.'
Ms Westwood's show started late, like every good fashion show. For 50 minutes, she produced a cavalcade of ideas: Oxford bags and tight little jackets, pink silk pyjamas, rich Spanish colours and ruffles, full organdie party frocks, silver foil denim jackets, and short drape dresses decorated with giant perspex orchid jewellery. It was vintage Westwood: mad, sometimes bad, sometimes spellbindingly brilliant. The designer had been studying the work of the great Parisian couturiers. She paid tribute to the Fifties with nipped-in jackets over long full skirts, and to classic British tailoring, with double-breasted blazers and Edwardian-cut suits. Cut is the core of the new Westwood philosophy. Afterwards, when she had kissed all the fashion editors and been interviewed by all the Japanese and American TV crews, she said, in her matter-of-fact way: 'There's some very nice cutting in my clothes. Creativity comes from technique, and technique is fundamental to my way of working.'
Here, then, was the reason why Ms Westwood chose the Grand Hotel. The greengrocer's daughter from Derbyshire - the onetime Queen of Punk - wanted to take her cutting techniques to the very centre of the traditional couture world.
She came, they saw, she conquered. Hail Vivienne, Queen of Couture.