c.2013 New York Times News Service

c.2013 New York Times News Service

The big news this London Fashion Week was supposed to be the return of Tom Ford to the runway, the London debut of L'Wren Scott (complete with a dinner Sunday night at the Cafe Royale co-hosted by her boyfriend, Mick Jagger), the buzz surrounding such rising stars as Christopher Kane and J.W. Anderson and the emergence of the young British model Cara Delevingne as "the next Kate Moss."

But for the thousands of young fans who packed New Oxford Street in central London on Saturday night, there was only one fashion designer who mattered this week: Rihanna.

The pop singer unveiled her first collection for the British retailer River Island, for which the British press has reported she is being paid roughly $1.2 million, at a cavernous club space jammed with revelers, a few curious members of the fashion press and the occasional local celebrity (including Delevingne, who sat in the front row, dressed in an Adidas hoodie, denim hot pants and thigh-high boots).

This, of course, was not the first dip into the fashion pool for Rihanna; she had already created two collections (largely of T-shirts, jeans and a leather jacket) for Emporio Armani jeans, with Giorgio Armani telling the press, "Rihanna is a great artist." More recently she told interviewers at the Grammys that she had partly collaborated with Azzedine Alaia on the custom-designed flowing, crimson gown she wore to the awards ceremony, saying he had showed her several designs before she picked the one she would wear.

On Saturday, as attendees mingled among the heavily female crowd during the hourlong wait for the show to begin a wait made somewhat easier by the small army of waiters passing out glasses of Champagne it seemed at times more like a girl's night out than a fashion show, with much of the overheard conversations being about last night's date or last week's breakup and almost no one talking about whether they would make it to Preen the next morning at 9.

As the crowd milled around, clearly interested in what Rihanna would show but perhaps even more interested in the after-party, a black-and-white film projected on the wall behind the bar showed on a continuous loop, with Rihanna apparently talking of the inspirations for her fashion line. I say "apparently" because the sound was turned off and you couldn't hear a word she was saying.

As for that after-party, Rihanna herself was a no-show, hitting the London club scene instead with some friends, an evening that quickly turned into tabloid fodder when a fan threw an energy-drink bottle at her, apparently angry that she was back with Chris Brown.

The runway, a multilevel set of platforms, resembled, appropriately, a concert stage; the models strutted out to the accompaniment of rap songs of which roughly every third word is unpublishable here. The clothes, designed in collaboration with Adam Selman, who has worked with the singer on her tour costumes in the past, were body-hugging and flesh-baring with even the modest cover-ups featuring some elements of see-through design. (You were expecting subtle?)

Selman told British Vogue that the collection was "urban-inspired, unfussy, with a bit of uptown," and that it was very much "based on Ri's style and her mood."

But he added that there was the occasional creative tension between the two partners. "There were times when I said to her, 'Ri, you've got to trust me on this,'" Selman told a reporter for the magazine's website. "Then she would put her foot down, and I'd have to let it go."

At the end, Rihanna came out in a form-fitting black minidress with Selman and flashed a quick, sly $1.2 million smile.