By Silvia Aloisi

VENICE (Reuters Life!) - Eight months after tearfully bowing out of fashion, Valentino returned to the red carpet with a film celebrating the man who dressed some of the world's greatest beauties from Jackie Kennedy to Princess Diana.

"Valentino: The Last Emperor" is an intimate, fly-on-the-wall look at Valentino's last two years at the helm of the fashion house he created in the 1960s, becoming a by-word for haute couture glamour over nearly half a century.

"I know what women want, they want to be beautiful," the Italian designer says at one stage in the film.

"That was always the thing for me, to design and create dresses. I am not capable of doing anything else," he adds.

The documentary follows Valentino from June 2005 to July 2007, when he held three days of lavish celebrations in Rome for the 45th anniversary of his fashion group.

He retired in January 2008 after his last fashion show in Paris, the culmination of months of speculation about his future as private equity firm Permira gradually took over his empire.

"Valentino" takes the viewer inside the studio where he created his dresses, backstage at the Paris fashion shows where socialites queued up to see his collections, and in villas around the world where he threw parties for royalties and stars.

It also captures the intense relationship between the designer and Giancarlo Giammetti, Valentino's business partner and companion for 50 years whose acumen was as crucial to the group's success as Valentino's creative talent.

Following them on yachts and jets are their six pug dogs, while an army of seamstresses -- some of whom have worked with Valentino for 35 years -- are tasked with bringing his vision to life in the Rome ateliers.

"It was something that really excited me having a documentary on my life being made," Valentino said on Thursday after the film was presented at the Venice film festival.

END OF AN ERA

He acknowledged that it was not always easy to have cameras and microphones around for such a long time.

"When I work and I create I am not very approachable, so having wires around me and knowing that everything was being recorded really did irritate me a little bit," he said.

Director Matt Tyrnauer, a U.S. journalist at Vanity Fair magazine, said the film did not lose any of its authenticity in the editing process, in which he said Valentino played no part.

"They put up with a lot. They were very brave ... They only screamed at us occasionally and we put most of it in the film."

Valentino is considered as one of the last of the great designers from an era before fashion became a global, highly commercial industry run as much by accountants and marketing executives as couturiers.

"After so many decades, after so much work, after so much freedom, can you imagine (them) telling me, 'You can't do this. You can't do that? I would eat them'," he says in the film.

Born in 1932 in the north of Italy and known throughout the world by his first name, Valentino's rise to fame coincided with the start of Italy's film heyday in the 1960s, immortalised by Federico Fellini's "La Dolce Vita".

From then on his signature scarlet evening gowns and conservative style made him a favourite for red carpet events, where he dressed the likes of Audrey Hepburn, Elizabeth Taylor and Julia Roberts.

But fashion's growth into a $127 billion industry is slowly threatening the old guard and ushering in a new breed of designers seen as better suited to lead expansion into new markets and product lines.

"I would like to leave the party while it's still full," Valentino says in the film, announcing his retirement.