It’s been three years since Hedi Slimane took over creatively at Saint Laurent—a move that continues to pay dividends for the brand. The facts alone are impressive: Sales went up a reported 37 percent in the third quarter of 2015—the strongest quarter to date for retail. Sales in Saint Laurent stores went up 32 percent, and wholesale sales went up 17 percent, reports Fashionista.

The numbers don’t lie. Having an influential creative director is key to the success of any fashion powerhouse. With Alexander Wang leaving Balenciaga and Raf Simons leaving Dior, you better believe that both labels will be looking to their successors (Demna Gvasilia took over for Wang at Balenciaga while Dior has yet to name Simons' replacement) to steer the brands to success—and sales.