The rumors have at long last been confirmed that Hedi Slimane is leaving Saint Laurent, the house that he renamed  and reinvented. In the four years that the designer served as creative director, Saint Laurent racked up double digit, year-to-year growth and is now a brand with yearly revenue of more than $1 billion. Slimane produced some of the industry's most discussed and debated collections  — beginning with his celebration of California youth culture and indie rock to his final Paris presentation that exploited the grotesquerie of 1980s ostentation.

In announcing his departure, François-Henri Pinault, the CEO of parent company Kering, said: "What Yves Saint Laurent has achieved over the past four years represents a unique chapter in the history of the house. I am very grateful to Hedi Slimane, and the whole Yves Saint Laurent team, for having set the path that the house has successfully embraced, and which will grant longevity to this legendary brand."

Slimane's tenure was dynamic and it was lucrative.  It was undeniably provocative. But did it mean anything?

In the ever-churning fashion industry, brands are regularly reinvented, modernized or transformed. But once a brand is reborn, the idea of sticking around to nurture its growth over time has become nearly obsolete. The designers who are brought in to lead an aesthetic upheaval are increasingly becoming short-timers. The average tenure is currently about three years. Can a foundation that is lasting and influential be constructed in so short a time?

Slimane's work at Saint Laurent — still widely called Yves Saint Laurent before he took over — helped spur a renewed interest in grunge. He was adept at taking the uniform of youth (at least as it is defined by a particular population of thin, mostly white, rock-a-philes) and up-marketing it. A dress that on the runway looked like a bedraggled Goodwill find, was, on closer inspection, extravagantly embroidered, constructed of fine silk and supremely expensive.

He took classics such as the women's tuxedo — le smoking — or the universal motorcycle jacket and cut them with a narrower silhouette, tweaked the proportions and made them sexier, but with an air of nonchalance. He gave the clothes attitude. His attitude. Yet, if one gave the collections some thought, it was possible to suss out the links to the brand's rich history: its long-standing celebration of youth culture, its fondness for the subversive, its delight in shocking.

Despite the exquisite construction, however, the clothes often looked common. The models in his final show — an examination of big shoulders, tight skirts and skyscraper pumps — looked like desperate strivers. The aesthetic was riddled with teasing cynicism. As commerce, the clothes seemed aimed at consumers' worst insecurities. The ones that have them convinced that expensive is always better and that certain labels can vouch for one's wealth and status. Slimane's was not always the work of fashion's better angels but it spoke powerfully about many of its consumers.

The clothes that Slimane produced during his time at Saint Laurent will likely not become part of the broader fashion vocabulary — ideas that other designers might use to expand the possibilities of attire. The house's namesake gave women now classic garments such as le smoking and the safari jacket. It's hard to imagine any of Slimane's creations finding a place in history. His hyper-skinny cuts have had significant impact on menswear, but that is a proportion that was realized during his tenure at Dior Homme from 2000 to 2007.

But Slimane did provoke thought. He made observers consider what should be declared precious. He placed renewed value on youth culture. Instead of calling Paris home base, Slimane lived in Los Angeles and he turned the fashion spotlight on that city — a part that existed beyond starlets, movies and the red carpet — in a way that no other designer has. His penultimate show was an ode to rock and roll at the Hollywood Palladium.

And even more than Balmain's Olivier Rousteing, with his army of Instagram devotees, Slimane stiff-armed the fashion industry's keepers of protocol and traditions. He refused to be judged. He didn't lift fashion up; but he didn't bring it down to street level either. His work was somewhere in between the optimism of high, flowery beauty and the clear-eyed ease of street style. It lived at the nexus of cynicism, willfulness, indulgence and self-regard. And consumers loved it.