Owner and founder Renzo Rosso hosted more than 25,000 guests at what seemed like an American state fair, except the kids were wearing destroyed denim. Country singers were replaced by a live Moby concert, and Naomi Campbell pranced around in a microscopic tartan kilt.

To top it off, Rosso treated the thronging crowd to a half-hour midnight fashion show that delivered Diesel fashions from the last 25 years, and re-created on stage (as well as on enormous video screens) some of the brand's most memorable advertising campaigns.

In typical self-deprecating kitsch, the day was kicked off with a marching band that brandished pom-poms and threw batons after Rosso announced, "I've always worked with passion and love for what I do and I'm very thankful. Bassano, this day is for you!" Campbell, her "I Dream of Jeannie" ponytail extension bouncing, promptly planted a kiss on the Italian magnate who was dressed in abused jeans, black ski cap and motorcycle shades.

Why the supermodel chose to split after making her very public appearance mid-day was as big a mystery as why her boyfriend, Matteo Marzotto, insisted on wearing business attire to a countryside bash hosted by fashion's most casual of brands.

One reason for Campbell's speedy exit could've been chalked up to the presence of ex-boyfriend Flavio Briatore, who partied with Santo Versace and Mario Boselli and stayed the course of the night in a private VIP section and watched as the sky exploded into color with a late night fireworks show.

It was a lavish, over the top affair and was probably the biggest spectacle the teenagers in Italy's Veneto region have ever laid eyes on, but this company has reason to celebrate.

Since its founding in 1978, the Molvena-based brand has steadily built itself into one of denim's most important players, all the while balancing an enviable cool status with enormous revenues of $660 million Euros. It's been an impressive feat, but founder Rosso said it didn't come easy.

"It's been 25 years of sacrifices and suffering," Rosso told FWD as he sat on a balcony overlooking the enormous crowd. "We really suffered for a long time trying to understand who were are, how we think and what our message would be. But our success has been so much more satisfying because it really wasn't easy."

Indeed, the days of sending out his destroyed jeans only to have them returned by vendors, who thought the holes and distressing were signs of defects have long gone. And it wasn't a one-man effort, which allowed the Diesel brand to explode, while Rosso went on to acquire manufacturer Staff International, as well as controlling interests in Martin Margiela and DSquared.

Rosso has made a habit of keeping a gang of trustworthy cohorts close by his side and most of these have been along from the start. His right hand business woman Marina Tosin, who is a major behind-the-scenes player at Diesel, has been with Rosso since day one, while Wilbert Das, the brand's creative director, came on board more than 15 years ago.

"It's incredible to see everyone's enthusiasm," Rosso said. "I am most proud when I see that each day going to work."

Das, who started when there were only 28 people in the company, told FWD, "It's changed from a very relaxed place where we were doing what we like, to an incredibly busy place where we're still doing what we like."

Things have certainly changed, but not too much. One look at Diesel's future with Rosso's two sons, 26-year-old Andrea and 24-year-old Stefano, is undeniable that these renegade street kids -- with their wild hair, unruly beards and laid-back style -- will continue the legacy of the brand for another 25 years of non-conformity.