Updated

Issa took center stage at London Fashion Week Saturday, showing why the exuberant Brazilian-born designer is one of the biggest beneficiaries of the upcoming royal wedding of Prince William and Kate Middleton.

The woman who enjoys the title of being one of Middleton's favorite designers is reaping serious benefits from Middleton's high profile support, including her decision to wear a sophisticated dark blue Issa dress when she and Prince William announced their engagement last fall.

"It's been amazing," Daniella Issa Helayel, known as Issa, said after her autumn and winter collection was unveiled in front of an overflow crowd of devotees.

"I design for myself and my friends, to flatter the figure, to celebrate women, and if people are happy, I'm happy," she said after the show.

The Middleton boost has helped Issa set in motion the planned opening of six stores in Brazil, with an expansion to New York possible. She has also expanded her online operations.

Issa, slightly overwhelmed by the waves of reporters and TV crews, declined to discuss Middleton's sense of style or to address speculation that she may design Middleton's wedding gown or perhaps the evening attire the bride will wear to a gala Buckingham Palace reception hours after she is wed.

"So much attention," she said to the waiting reporters, far more than she had encountered after past shows. "What have I done?"

Told she has surpassed Lady Gaga as one of the most sought after figures on Internet search engines, she said: "It's not me, it's Kate." And she cautioned that her newfound fame could evaporate if her designs fall flat: "You're only as good as your last collection."

But she is clearly enjoying the commercial bounce that followed the engagement, which sent her already highpowered career into the buzzier regions of hyperspace.

Some of the outfits in the show were clearly too revealing for Middleton in her new role as princess-to-be. But many of the signature jersey dresses with cinched waists and an elegant feminine silhouette may find their way into Middleton's closet, and those of Madonna and Scarlett Johansson, who have both worn Issa in the past.

Issa has an imaginative touch with colors — she said Brazil is reflected in her choices — and this collection was filled with slouchy pantsuits and wrap dress and accessories like elaborated shaped hats, dangly gold jewelry and long suede gloves.

The models wore long, dramatically shaped hair extensions that billowed behind them as they strode the catwalk.

Despite her Brazilian heritage, Issa has been based in London for a decade, carving a reputation as a designer whose clothes are sexy but not too sexy, fashionable but still wearable by normal women of normal height. She said she designs with all types of figures in mind.

She has become a true Brit, citing Queen Elizabeth II as her ultimate icon, and jotting down her fashion ideas in a chic (and expensive) Smythson diary, the kind favored by Middleton as well.

KINDER AGGUGINI

Aggugini shunned the glitz of fashion week headquarters at Somerset House, opting to host his show at a tiny showroom in central London. Models walked a zigzag path that worked around the seated guests, showing off a series of highly structured wool coats — some with abstract flower-shaped cut outs — over dark skinny jeans and short pencil skirts.

Black and cream cashmere wools dominated, punctuated by scarlet, mustard yellow and a summery white and pink floral printed silk that was used in dresses — and surprisingly, in a thick parka.

Aggugini said a key look was his geometric, cape-like coats with cropped balloon sleeves. He said the collection was an arty mix of '50s French couture and '80s Japanese conceptual fashion, inspired by the style of art collector Peggy Guggenheim.

"Fashion needs to be hand-finished, it needs to be special," to differentiate from the designer copycat looks churned out by high street shops, he said.

JOHN ROCHA

The elaborate, oversize black headgear adorning the models in John Rocha's autumn and winter collection threatened to overshadow — literally — the dresses on display. They looked something like Aztec headpieces, with elaborate construction and seemingly a life of their own.

The dresses were mainly in black and dark gray, and included sexy overcoat dresses. Many of the outfits had sheer black trousers worn with black underwear, giving the outfits a light, gliding feel. He also showed a dramatic red trench coat and a dress that took its inspiration from traditional pea coats.

His menswear, described in the program as slightly eccentric, included a tight-fitting suit with a fur collar, and a number of outfits based on tailored overcoats in place of suit jackets.

JONATHAN SAUNDERS

Jonathan Saunders worked magic with the primary colors, presenting a collection of sleek, featherlight dresses in jewel tones of rich red, green and blue.

Models with hair pulled back in clean, simple ponytails wore high-collared silk satin blouses and below-the-knee sheath dresses.

Although high slits showed the occasional flash of thigh, the overall style was conservative and demure. Chunky platform shoe-boots in metallic and velvet kept the look modern and balanced the lightness of the silk garments.

Burgundy was a key color, with many blouses, blazers and dresses also made with colorful, intricate art nouveau-inspired silk screen prints_a signature technique of Saunders.