Egon von Furstenberg, son of a nobleman who gave up a career in banking to become a popular fashion designer, died Friday in a hospital in Rome, where he had been residing. He was 57.
His office released a statement confirming his death but did not give the cause.
Carla Nani Mocenigo, a fashion publicist and friend of Von Furstenberg, said that he had recently developed bronchitis. This week his condition "suddenly got much worse," she told Reuters news agency.
Born in Lausanne, Switzerland, Von Furstenberg inherited his title of prince from his father's side of the family, but most of the family fortune came from his Italian mother, Clara Agnelli of the Fiat automobile empire.
He attended the University of Geneva, where he met his future wife, Diane Halfin, a Belgium native who launched her own fashion line under the name Diane von Furstenberg after the couple married in 1969.
They lived in New York City, where he worked at Chase Manhattan Bank for several years before changing course and enrolling at the Fashion Institute of Technology.
The Von Furstenbergs' whirlwind social life and his aristocratic heritage made them a frequent item in New York's society pages. They were photographed at discotheques and parties.
"We went everywhere," Diane von Furstenberg recalled in an interview with Newsweek magazine in 1976. "Even to the opening of a toothpaste factory."
The couple lived in two apartments on Park Avenue in New York City, one for them and one for their children, Alexandre and Tatiana, who were toddlers at the time.
Von Furstenberg made no secret of his attitude toward open marriage. "After a while, passion cools," he said in an interview with New York magazine in 1973. The couple separated that year and divorced in 1983.
He took a job as a buyer for Macy's department store in the early 1970s and met a wholesale manufacturer who asked him to design a collection for large-size women. He launched that line in 1975 and soon afterward started his own business with a menswear collection.
His logo, a star hovering above a crown, suggested his royal ancestry. The press referred to him as "the prince of high fashion." He moved his base of operations to Milan, Italy, in 1977 and later added an office in Rome, where he lived in a Renaissance palace near the Pantheon.
Von Furstenberg expanded his business to include women's wear, accessories and home furnishings, with a number of licensing agreements and boutiques.
He also wrote several books, including "The Power Look" (1978), a clothes-make-the man volume, and "The Power Look at Home: Decorating for Men" (1980), with co-author Karen Fisher, about single men's decorating styles.
"Knowing I could create a place for myself without a woman's touch and also love the results was one way for me to take control of my own life," he said in an interview with the Los Angeles Times while promoting his home decor book.
He married his second wife, Lynn Marshall, in 1983. It was not immediately clear if they were still married at the time of his death.
Von Furstenberg remained on friendly terms with his first wife, who still designs under the Von Furstenberg name and is perhaps best known for the wrap dress. He attended the wedding when she married media mogul Barry Diller in 2001.
"With two kids and grandchildren, we talk almost every day," he told the New York Times in July 2001.
Von Furstenberg is survived by his children and several grandchildren.
His funeral is scheduled for today in Rome, and burial is planned for Monday in a family tomb in Austria, according to the Guardian newspaper of London.