Raf Simons, who began his career in 1995, is generally acknowledged as one of the most influential designers of his generation. “He did everything before anyone else, and everybody has copied him,” the Paris stylist and editor Marie-Amélie Sauve said in The New York Times Magazine in 2005.

Although Mr. Simons had not sought media exposure to the extent other designers have — for years he gave few interviews and disliked having his picture taken — the attention came to him in 2005, when he was named creative director of Jil Sander. The brand had been a creative force until its namesake and founder sold it to Prada in 1999, after which it experienced management turmoil. (In 2006, Prada sold the Sander brand to a group of investors in London.)

Mr. Simons quickly restored the label’s modernist vision, with men’s and women’s collections known for sharp tailoring and intense colors. At the same time, he found a new audience with women’s editors and buyers. In his spring 2008 women’s line for Jil Sander, Mr. Simons seemed confident to offer new proportions and to experiment with layers of transparent fabrics.

The designer commutes between Antwerp, where he produces his own men’s wear label, and Milan, where the Jil Sander company in based.

Mr. Simons was born on Jan. 12, 1968, in a Belgian village near the German border, where his father had served in the military. He studied industrial design at a university in Genk. While taking an internship with the fashion designer Walter Van Beirendonck in Antwerp, he began to think about clothing design. But he was already too old to enroll in the Royal Academy of Fine Arts, which had graduated designers like Dries van Noten and Martin Margiela. His ideas about men’s fashion, however, were already well formed.

In 1995, he made his first collection, acknowledging the influence of Helmut Lang on the slim silhouette he created. He continued to refine his ideas about masculinity and, in the summer of 1998, at the Paris men’s shows, he presented one of his most affecting statements about youth. He staged his show on a series of concrete overpasses, with the surrounding neighborhood reflected in a huge silver sphere. The audience had the perspective of seeing the models approach from a great distance — a single line of men walking at dusk from overpass to overpass.

Although his early collections seemed dark and forbiddingly cool, Mr. Simons’s perspective is essentially that of a romantic. He sees things simply and directly, but from a distance.

In 2004, Mr. Simons won the $120,000 Swiss Textile Federation prize. That year marked a maturing in his approach, from reactive to exploratory, as he focused on innovative fabrics and design. He continues that approach at Jil Sander. — Cathy Horyn