At Variety, we talk a lot about the soft power of the red carpet. We live in an age where “image architect” is a vaunted job title, thanks to the serious economic and cultural impact the right look can offer stars and brands.

We can largely thank Valentino Garavani, who died at 93 on Monday, for creating this mutually beneficial relationship. In the late ’70s, European fashion houses became global enterprises. As the designer of deeply glamorous and dreamlike gowns, Mr. Valentino (as he was known) saw the writing on the wall. Celebrities and artists — particularly actresses — would come to reinvent how fashion captivated culture and commerce. His muses are renowned, from Jackie Kennedy to Gwyneth Paltrow, Julia Roberts to Cate Blanchett.

Celebrated documentary filmmaker Matt Tyrnauer (above, far right) chronicled the designer’s opulent lifestyle and pioneering spirit in the 2008 movie “Valentino: The Last Emperor.” The project premiered at the Venice Film Festival that year, and would spark a subgenre of fashion docs that gave glimpses into the pain, mess and belief it takes to inspire the masses and sell big.

We caught up with Tyrnauer just hours after the Valentino news hit, drawing tributes from the likes of Paltrow and Colman Domingo, to discuss the designer’s legacy in show business and his notoriously mercurial personality.

Your movie, now almost 20 years old, shows how prescient Valentino was in bringing celebrities into the fashion world. What will his legacy be in our town?

Valentino was at the forefront of Hollywood’s love affair with fashion in the late 20th century and the early 21st. He was one of the first high fashion designers to embrace movie stars hardcore. Before that, fashion was really focused on socialites and aristocrats. It was Valentino and his partner, Giancarlo Giammetti, who really pushed hard to have actresses wear his clothes. Being a global movie star at that time was an extraordinarily potent type of fame. Fashion began to be redefined by movie stars wearing your clothes, not only out in public or on the red carpet, but sometimes in the films themselves. Valentino was essential for that movement from high society to Hollywood being an important part of the fashion universe.

Who were some of his biggest muses?

Elizabeth Taylor and, in Italy, Monica Vitti were two of the first. Through the years, we saw Gwyneth Paltrow, Anne Hathaway, the “Kates” (meaning Cate Blanchett and Kate Winslet), Claire Danes, Julia Roberts. It was Jackie Kennedy, though not a movie star, who was the glamorous woman who made him a household name. She was the first First Lady to bring a movie-star-level candlepower to that position.

You had unprecedented access to Valentino for your film. What’s the thing that will stay with you?

I never saw anyone live a lifestyle like Valentino. It was so over the top, beyond description. There were villas and chateaus and chalets and Fifth Avenue apartments. Not one pug, not two pugs, but five pugs. And multiple servants in white gloves to tend to the pugs. Gianni Agnelli famously said, ”I live like a king, but Valentino lives better than me. And I don’t know how he does it.”

You were very open about having big creative disagreements with Valentino during filming. How do you reflect on it now?

What really defined the whole production was the warm embrace of Valentino, and then the really unspeakable tantrum. It was a seesawing motion throughout, and I put some of that in the film. He had no editorial control over the film. He hated the film. When he first saw it, it premiered at the Venice Film Festival. He got a 10-minute standing ovation after, and he quickly turned into a big fan of the film. He was extraordinary at doing the press attendant to the film, which was a surprise hit. I have nothing but affection and fondness and respect for Valentino and Giancarlo Giamatti. They were absolutely extraordinary people to spend that much time with, and they really did let me into their world. It was extremely brave. At the end of the day, we went into the success of the film arm-in-arm. It was an unforgettable moment. And it really did go around the world, and it was a very happy ending.