As much as anyone, Hugh Hefner turned the world on to sex.

As the visionary editor who created Playboy magazine out of sheer will and his own fevered dreams, he introduced nudity and sexuality to the cultural mainstream of America and the world.

For decades, the ageless Hefner embodied the "Playboy lifestyle" as the pajama-clad sybarite who worked from his bed, threw lavish parties and inhabited the Playboy Mansion with an ever-changing bevy of well-toned young beauties. He died Sept. 27 at the age of 91. His death was confirmed by Playboy in a tweet.

From the first issue of Playboy in 1953, which featured a photograph of a nude Marilyn Monroe lounging on a red sheet, Hefner sought to overturn what he considered the puritanical moral code of Middle America. His magazine was shocking at the time, but it quickly found a large and receptive audience and was a principal force behind the sexual revolution of the 1960s.

Hefner brought nudity out from under the counter, but he was more than the emperor of a land with no clothes. From the beginning, he had literary aspirations for Playboy, hiring top writers to give his magazine cultural credibility. It became a running joke that the cognoscenti read Playboy "for the articles" and demurely averted their eyes from the pages depicting bare-breasted women.

Few publications have so thoroughly reflected the tastes and ambitions of their creators as Hefner's Playboy. "I'm living a grown-up version of a boy's dream, turning life into a celebration," he told Time magazine in 1967. "It's all over too quickly. Life should be more than a vale of tears."

The magazine's formula of glossy nudes, serious writing and cartoons, coupled with how-to advice on stereos, sex, cars and clothes, changed little through the years and was meant to appeal to urban, upwardly mobile heterosexual men.

But Playboy also had a surprisingly high readership among members of the clergy -- who received a 25 percent subscription discount -- and women.

"Hefner was, first and foremost, a brilliant businessman," David Allyn, author of "Make Love, Not War: The Sexual Revolution, an Unfettered History," told The Washington Post in an interview. "He created Playboy at a time when America was entering a period of profound economic and social optimism. His brand of sexual liberalism fit perfectly with postwar aspirations."

"Hef," as he was widely known, was in charge of editorial operations from the beginning and was known to work on the magazine for 40 hours without a break, driven by the deadline buzz of amphetamines, Pepsi-Cola and his ever-present pipe. He hired a large staff of editors and artists who brought literary sophistication and visual dash to the pages of Playboy, but there was never any doubt that the guiding vision behind Playboy was Hefner's, and his alone. For many years, the magazine was produced in his home town of Chicago.

Before he turned 50, Hefner was, as Esquire magazine once decreed, "the most famous magazine editor in the history of the world."

He commissioned articles by some of the world's most celebrated writers -- Saul Bellow, Norman Mailer, James Baldwin and Joyce Carol Oates, to name a few. Among the works that first appeared in Playboy were excerpts from Alex Haley's "Roots," Larry L. King's "The Best Little Whorehouse in Texas," Cameron Crowe's "Fast Times at Ridgemont High," John Irving's "The World According to Garp" and Bob Woodward and Carl Bernstein's "All the President's Men."

The magazine's in-depth interviews with leading figures from politics, sports and entertainment -- including Muhammad Ali, Fidel Castro and Steve Jobs -- often made news. One of the magazines's most newsworthy revelations came in 1976, when presidential nominee Jimmy Carter admitted in a Playboy interview, "I've looked on a lot of women with lust. I've committed adultery in my heart many times."

Each month, Hefner wrote an editorial in which he sought to define the "Playboy Philosophy." In his view, sexual freedom was part of a larger spirit of liberty, including free speech, relaxed drug laws and civil rights, including gay marriage.

Hefner's umbrella organization of Playboy Enterprises grew to include television shows, jazz festivals, book publishing and an international chain of Playboy clubs, where cocktail waitresses, known as bunnies, wore revealing satin outfits with fluffy white tails.

In 1961, when independently owned Playboy clubs in Miami and New Orleans refused to admit African-American members, Hefner bought back the franchises and issued a sternly worded memorandum: "We are outspoken foes of segregation and we are actively involved in the fight to see the end of all racial inequalities in our time," he wrote.

At the Playboy Mansion -- first in Chicago and later in Los Angeles -- Hefner held glittering parties that attracted Hollywood celebrities and scores of women who eagerly shed their clothes. Outside the front door, a sign read, "Si non oscillas, noli tintinnare" -- a Latin phrase loosely translated as "If you don't swing, don't ring."

Once-forbidden sexual imagery and ideas popularized in the pages of Playboy became commonplace in film, television and other media, as the culture at large came to reflect the values Hefner espoused.

"We will never recapture the importance of Playboy in the '60s and '70s," he told The Washington Post in 2003, "because we changed the world. We live in a Playboy world now, for good or ill."

Although he took offense at anyone who called him a pornographer, noting that Playboy seldom, if ever, depicted overt sexual acts, Hefner relished denunciations from religious groups and self-appointed protectors of morality.

Still, he was caught off guard by the outrage of feminists who found his magazine's depictions of women degrading. Feminist writer Gloria Steinem briefly worked at a Playboy Club in New York City to gather background for an undercover article she wrote in 1963.

In a 1970 appearance on the "Dick Cavett Show," author Susan Brownmiller confronted Hefner, saying, "When Hugh Hefner comes out here with a cottontail attached to his rear end, then we'll have equality."

Hefner remained silent.

"Quite frankly," he said on the NPR interview program "Fresh Air" in 1999, "the women's movement from my point of view was part of the larger sexual revolution that Playboy had played such a large part in."

Over time, some women came to view Playboy with greater acceptance, if not respect. Feminist scholar Camille Paglia approvingly pronounced Hefner "one of the principal architects of the modern sexual revolution" in a 1999 documentary.

When "Sex and the City," a television series about four sexually adventurous women in New York, premiered in 1998, the lead character played by Sarah Jessica Parker wore a necklace depicting the Playboy bunny.

'No drinking, no smoking, no swearing'

Hugh Marston Hefner was born April 9, 1926, in Chicago. His father was an accountant, his mother a teacher, and he grew up in what he called a conservative household of "rigid Protestant fundamentalist ethics."

"There was no drinking, no smoking, no swearing, no going to movies on Sunday," he recalled in a 1962 interview with the Saturday Evening Post. "Worst of all was their attitude toward sex, which they considered a horrid thing never to be mentioned."

After serving in the Army during World War II, Hefner graduated in 1949 from the University of Illinois, where he majored in psychology.

While working in the personnel office of a box manufacturer and as an advertising copywriter for a department store, he tried without success to become a cartoonist. He later worked in promotions for Esquire magazine and held other publishing jobs while developing the idea for Playboy.

With $600 of his own savings and investments from friends and family -- including his parents -- Hefner wrote most of the first issue of the magazine himself. He purchased the rights to the nude photograph of Monroe, originally shot in 1949 for a calendar. ("I had nothing on but the radio," Monroe once quipped.)

Hefner had planned to call his magazine Stag Party, but when the publishers of another men's magazine named Stag threatened to sue, a colleague came up with an inspired afterthought: Playboy.

The magazine hit the newsstands in December 1953 and quickly sold out its press run of more than 50,000 copies.

For Playboy's second issue, an art director drew a cartoon-like bunny's head with a bow tie. It became the enduring symbol of Playboy, often disguised within the cover photo on the magazine. Beginning in 1955, another of the magazine's defining features was its centerfold, highlighting the "Playmate of the Month" in a glossy color photograph. Nude pictorials of actresses and other celebrities often appeared in Playboy, but the centerfold Playmates were chosen for what Hefner called a "girl-next-door" quality. Some of them, such as Anna Nicole Smith, became famous as sex symbols, but even she was unknown when she first appeared in Playboy in 1992.

The nude pictures grabbed public attention, but the substance and variety of the magazine's other features -- interviews, cartoons, serious journalism and fiction -- set Playboy part from other skin magazines. Hefner rejected tawdry advertising in order to cultivate a more sophisticated, worldly image.

"Playboy straddles the line between pornography and anti-pornography," Allyn, the historian and author, wrote in an e-mail to The Post. "Conventional pornography . . . tends to relish in, and celebrate, vulgarity, whereas Playboy treats the vulgarity of conventional pornography with disdain."

Shortly before Hefner married Mildred "Millie" Williams in 1949, she confessed to him that she had had an affair with another man. The wedding went ahead, and the Hefners had two children, but Hefner later said the revelation shattered any illusions he held about the virtue of women.

"I was absolutely devastated," he told the Los Angeles Times in 1994. "I'm sure that in some way, that experience set me up for the life that followed."

Embodying the Playboy image

Even before his divorce in 1959, Hefner sought to embody the Playboy image of the carefree, urbane man about town. For a while, at least, his life was synonymous with that of his magazine and the budding Playboy empire.

From 1959 to 1961, he had a syndicated television show, "Playboy's Penthouse," with top jazz stars entertaining at intimate gatherings in Hefner's home. It was one of the first television shows in which black and white guests interacted as social equals. Another show featuring Hefner, "Playboy After Dark," aired for two seasons, beginning in 1969.

The magazine reached the height of its popularity in the early 1970s, with a circulation of 7 million. Hefner's personal fortune at the time was estimated at more than $200 million, and he traveled in a black jetliner with the bunny-head symbol painted on the tail. The Harvard Business School studied his formula for success.

Before long, though, the Playboy franchise began to weaken. In 1974, Hefner's longtime assistant, Bobbie Arnstein, was convicted of conspiracy to distribute cocaine and later committed suicide. Hefner was not implicated in any wrongdoing, but he was repeatedly investigated by the FBI and Internal Revenue Service and was named on President Richard M. Nixon's "enemies list."

He also battled postal authorities and federal commissions that sought to restrict the magazine's distribution. Other publications, such as Penthouse and Hustler, cut into Playboy's readership by publishing more explicit photos, and several of Playboy's spinoff businesses lost money.

In 1980, 20-year-old Playmate of the Year Dorothy Stratten was killed by her estranged husband in a murder-suicide. Hefner's detractors held him indirectly responsible, saying Stratten had been caught up in Playboy's hedonistic milieu.

After a stroke in 1985, Hefner stopped smoking his familiar pipe, and three years later he stepped aside as Playboy's chief executive in favor his daughter, Christie Hefner, though he retained his title as editor-in-chief of the magazine until his death. The magazine remained headquartered in Chicago until the editorial operation was shifted to New York in 2002 and later to Los Angeles.

Christie Hefner resigned as chief executive in 2009 amid financial struggles for Playboy Enterprises. Hefner led an effort to buy back the company's stock, making it a privately held corporation by 2011.

After his divorce from his first wife, Hefner often said he would never marry again. He had a long relationship in the 1970s and 1980s with onetime Playmate Barbi Benton, but they did not marry.

In 1989, when he was 63, he married 26-year-old Playmate of the Year Kimberley Conrad. They had two sons, Marston Hefner and Cooper Hefner. The couple separated in 1998 and divorced in 2010.

On New Year's Eve 2012, Hefner married another onetime Playmate, Crystal Harris. He was 86 at the time; she was 26.

In addition to his wife and sons, Hefner's survivors include two children from his first marriage, Christie Hefner and David Hefner.

Well before his marriage to a woman 60 years his junior, the aging Hef had become something of a self-caricature, strolling the grounds of the Playboy Mansion in silk pajamas, accompanied by a troupe of women who never seemed to turn 30. He acknowledged sleeping with "more than a thousand" women and often touted the efficacy of Viagra. From 2005 to 2011, the adverntures of the young women who inhabited the Playboy Mansion were chronicled in a cable reality show called "The Girls Next Door."

Away from his magazine and his every-day-is-a-party approach to life, Hefner was a generous if unheralded philanthropist. In the 1970s, he led a fundraising effort to restore the renowned Hollywood sign on a Los Angeles hillside. In 2010, he contributed $1 million to prevent real estate development near the sign. He also donated millions to efforts to preserve classic films and endowed a chair for the study of cinema at the University of Southern California.

Well into his 80s, Hefner continued to edit his magazine and did his best to maintain his swagger as the unflappable, unstoppable and unrepentant king of the Playboy way of life.

"I have not become jaded," he told The Washington Post in 2003. "I wake up every day well aware of my good fortune, loving the work I do, loving my life, realizing that life is a crapshoot and I'm on a roll second to none."