Fledgling director and Vanity Fair special correspondent Matt Tyrnauer filmed 270 hours of the final two years of Italian haute couture designer Valentino Garavani’s career before his 2007 retirement, capturing the absurdly opulent life of the small, bronzed man he calls both a genius and “a bossy nightmare.”

At the Chilmark Community Center last Wednesday night, Mr. Tyrnauer showed his first independent film, Valentino: The Last Emperor, to a full house. The film, recorded in Italian, English and French, is from a filmmaker who has described himself as a T-shirt and jeans guy. The 96-minute, fly-on-the-wall chronicle is less a tale of high fashion than a story of friendship between Valentino and his lover and business partner, Giancarlo Giammetto.

The film began as a Vanity Fair feature assignment. Mr. Tyrnauer, who has no interest in fashion, spent three weeks in Rome reporting on the partnership between Valentino and Giancarlo. At first glance, Mr. Tyrnauer saw Valentino as a guiltlessly rich, dictatorial diva with two talents, two passions and two interests: beauty and surrounding himself with it.

“Then I did some research about [Valentino] which led me to believe even further that I did not want to meet him or write about him,” Mr. Tyrnauer says.

But Mr. Tyrnauer soon became captivated by Valentino and Giancarlo’s companionship. The boyfriends-turned-business-partners have spent only a few weeks apart in the past 50 years. In the 1960s, when Valentino first began stitching his now-iconic name onto the tags of his lavish couture dresses, he fell into bankruptcy. Valentino, the designer, and Giancarlo, the businessman, then formed a partnership that would result in Valentino’s 45-year reign over the high fashion industry.

“[Giancarlo] is the noble protector of Valentino,” Mr. Tyrnauer says. “You don’t get to be the richest man in Rome without someone watching the counting house.”

The nugget of the documentary is this relationship — unbalanced in power and prestige but reciprocal in love.

“There would be no Valentino without Giancarlo, and that for me is the story of the film, which is a very universal story. It’s a love story,” Mr. Tyrnauer says, adding, “In the end I don’t think you see [Valentino] as someone who wears the $100,000 watch and the $7,000 suit, you see two people whom you can relate to . . . The thing you aspire to is not the boat or the castle, it’s the love.”

From Valentino’s château in Paris to his villa in Rome, Mr. Tyrnauer captures all sides of the designer dynasty: the seamstresses who hand-sewed Valentino’s original collections of $100,000 Grecian drapery-styled dresses; fashion icon Countess Jacqueline de Ribes, who totes her own bottle of vodka to Valentino soirees; and Maggie, Margo, Maude, Milton and Molly, Valentino’s five white-toothed pugs who pitter-patter after him like the rest of his surrounding crew.

Valentino, with his band of guardians, Mr. Tyrnauer says, was most challenging to work with.

“Valentino has a breakdown at 12:45 and 7 p.m. every day. He quit the movie several times each day and rehired himself the next morning. I began to call [Giancarlo and him] Liz and Dick to their faces because that’s how they were to work with.”

One highly resisted (at first) and invasive task was wiring Valentino and Giancarlo with microphones, a daily process that required the pair to remove their jackets, unbutton their shirts and undo their ties. Taking a tip from a colleague, Mr. Tyrnauer airlifted male models to Italy. He trained the chiseled men to wire the documentary stars with microphones, and before long, the process became a most invited task. Valentino would ask, in his thick Italian tongue, “Darling, when are we going to do the microphones today?”

“So the one time in 50 years Giancarlo decides to tell Valentino that he looks too tan, we had it,” Mr. Tyrnauer says.

Mr. Tyrnauer first showed the documentary to Valentino and Giancarlo in a screening room in London.

“When the lights came up, I thought they looked like people who had escaped from the movie One Flew Over the Cuckoo’s Nest,” Mr. Tyrnauer says. “They were just devastated by the film. They hated it. Valentino thought that there was no fashion, no glamour, no celebrity, that he wasn’t portrayed in a glorious enough light . . . .”

After the showing, Valentino and Mr. Tyrnauer engaged in a six-month war over the release of the film. Mr. Tyrnauer suited up with an army of 18 lawyers, and won.

The premiere at the Venice International Film Festival drew about 500 paparazzi and an adoring audience. Valentino and Giancarlo watched the film for a second time from a back-wall balcony above the audience. “After the film, [Valentino] received a very longstanding ovation, which Valentino received in the manner of Mussolini,” Mr. Tyrnauer says, slowly sweeping an extended right arm overhead in mimic. “Giancarlo was pulling at his coat tails trying to get him to sit down. Then both of them burst into tears and then he fell in love with the movie, a complete 180-degree reversal. He invited me to the yacht for a toast with Champagne.

“His last words to me were, ‘Matt, I really want an Oscar.’ We didn’t have the heart to tell him that I would win the Oscar, not him.”