The Christian Dior heritage began with the romantic Mr. Dior himself, a man who brought femininity to the postwar 1950s, building the tiny waists and sweeping skirts of his voluptuous “flower women” on his obsession with the Edwardian elegance of his early memories of his mother. He died suddenly in 1957 after only 10 years at the helm, to be followed by a young unknown, Yves Saint Laurent.

Mr. Simons’s style could not be more different from that of the founder: He has a modernist vision and a spare, linear style based on fine tailoring. “My aim is a very modern Dior, but at the end of the day, I also look back,” he said, referring to what he calls “mid-century modernism.”

“I find that period between 1947 and 1957 extremely attractive, and there was a lot of modernity,” Mr. Simons said of Christian Dior’s designs. “There was the romantic appeal looking back to his mother and the belle époque, but there was also a constant evolution in shape, changing proportions and the ideas connected to the World War were revolutionary.”

Mr. Simons comes from the Flemish town of Neerpelt, the only son of a modest family. His mother worked as a house cleaner and his father was on military night watch. Some of that uniform severity may have been worked into the spare lines of early men’s collections, where the obsessive focus was the angst and tension of youth culture and the beat of the Belgian music movement.

“But my father was not a strict man, it was a warm nest,” Mr. Simons said, adding that his interest in fashion was more about escaping from a Catholic background and a rigorous college full of students aspiring to become lawyers or doctors.

While Christian Dior embraced flower gardens and the decorative stage sets of his artist friend Christian Bérard, Mr. Simons trained as an industrial designer in Genk before trying men’s fashion. His world was defined by one of his earliest shows for autumn winter 1996-97. In “We Only Come Out at Night,” youths with skinny bodies, sculpted faces and sensual lips dragged on cigarettes and reveled in their adult-free world.