Playboy founder Hugh M. Hefner, the pipe-smoking hedonist who revved up the sexual revolution in the 1950s and built a multimedia empire of clubs, mansions, movies and television, symbolized by bow-tied women in bunny costumes, has died at age 91.

Hefner died of natural causes at his home surrounded by family on Wednesday night, Playboy said in a statement.

By the 1970s, the magazine had more than 7 million readers and had inspired such raunchier imitations as Penthouse and Hustler. Competition and the internet reduced circulation to less than 3 million by the 21st century, and the number of issues published annually was cut from 12 to 11.

In 2015, Playboy temporarily ceased publishing images of naked women, citing the proliferation of nudity on the internet but restored its traditional nudity earlier this year.

Hefner and Playboy remained brand names worldwide.

Playboy proved a scourge, and a temptation. Drew Barrymore, Farrah Fawcett and Linda Evans are among those who have posed for the magazine. Several bunnies became celebrities, too, including singer Deborah Harry and model Lauren Hutton, both of whom had fond memories of their time with Playboy. Other bunnies had traumatic experiences, with several alleging they had been raped by Hefner's close friend Bill Cosby, who faced dozens of such allegations. Hefner issued a statement in late 2014 he "would never tolerate this behavior." But two years later, former bunny Chloe Goins sued Cosby and Hefner for sexual battery, gender violence and other charges over an alleged 2008 rape.

One bunny turned out to be a journalist: Feminist Gloria Steinem got hired in the early 1960s and turned her brief employment into an article for Show magazine that described the clubs as pleasure havens for men only. The bunnies, Steinem wrote, tended to be poorly educated, overworked and underpaid. Steinem regarded the magazine and clubs not as erotic, but "pornographic."

"I think Hefner himself wants to go down in history as a person of sophistication and glamour. But the last person I would want to go down in history as is Hugh Hefner," Steinem later said.

Well past retirement age Hefner continued to take an active role in the editorial side of his magazine, choosing covers and Playmates each month.

Late into his life he also frequented nightclubs and maintained a bevy of young girlfriends, a lifestyle he credited with keeping him young both in and out of the bedroom.