He had talent, designing the daring pillbox hat for Jacqueline Kennedy that startled a nation and started a craze. He had style, responding to the 1977 New York City blackout by summoning dozens of friends—including Liza Minnelli and disco-owner Steve Rubell—to a shimmeringly candlelit party in his East Side town house. And he had energy, persuading a Senator’s wife named Elizabeth Taylor Warner to toss a sable coat over her nightgown to give him a midnight tour of Washington, D.C. Then he awoke at dawn to fly back to New York just in time to preside over a fashion runway that morning.

He lived so fast that his first and last names blew off in the propwash, unsleek encumbrances discarded in the service of a style that stood for stripped-down elegance. The first American designer to rocket to international stardom did it with simple syllables that put his middle name on the look of the ’70s. It was a style as spare and as unrevealing as the mirrored sunglasses behind which the real Roy Frowick surveyed a curious world. Suave and gracious, he was a kind of Jay Gatsby of Manhattan nightlife, a mysterious, aspiring Midwesterner who altered his name and re-created himself in a tanned and tuxedoed image of breathless glamour. It was Halston whose parties helped transform a cavernous Manhattan space called Studio 54 into the disco of the decade. It was Halston whose friendships with Liza and Liz gave a hot center to the celebrity culture and established him as the walker to the stars. And it was Halston whose simple designs in cashmere and Ultrasuede defined a newly self-confident American fashion sense. Gushed Women’s Wear Daily: “The 1970s belong to Halston.”

In equally spectacular fashion, the ’80s did not. A chain of business blunders cost him control of his empire and, eventually, the right to design under his own name. In late 1988 he found he was carrying the AIDS virus. The blows continued. Last year his former friend’s revelations of drugs and debauchery in The Andy Warhol Diaries left him feeling embarrassed and betrayed. Like Gatsby, his dreams busted up before he did.

The end came at 11:22 P.M. on March 26 in Room 670 at Pacific Presbyterian Medical Center in San Francisco. Halston, 57, succumbed to Kaposi’s sarcoma, an AIDS-related cancer, after an 18-month struggle with the disease whose chilling toll has already devastated the fashion industry (see following story). An exceedingly private person, he had rarely discussed his illness, even with close friends. But his older brother, Robert Frowick, 60, a retired foreign-service officer, resolved to make the cause of death public. “We decided we should be straightforward with everyone,” he said at a press conference last week. “We think it’s best for all concerned to know the reality. We profoundly hope it has a positive impact on the public.”

Last year the ailing Halston put his beloved town house up for sale (it was sold in January for $5 million) and unloaded his Montauk, Long Island, estate. He moved in January into a $1000-a-day suite at the Mark Hopkins hotel in San Francisco to be near his family and his doctors, Charles MacDonald and Robert Rodvein. “He knew he was dying,” says Halston’s longtime friend and publicist, Barry Landau. “He wanted to get away from the pressures of New York. He wanted some dignity.”

To thwart the tabloids, Halston registered at the hospital as Mr. Condencia when he checked in for the last time at the beginning of March. His final home was a pale-green hospital room with a view of a nearby park and the Golden Gate Bridge. Surrounded by a half dozen potted white orchids, the ever-elegant designer sat propped up in bed wearing fresh white linen shirts and a plush red robe.

Robert, another brother, Donald, 44, and sister Sue Watkins, 52, routinely made the 90-minute drive from their Santa Rosa homes to visit their sick sibling, whose “two biggest pleasures,” according to Robert, had become “food and touring.” To indulge the former, the family brought good china, nice silver and fresh lobster salad. To facilitate the latter, Halston purchased a $200,000 Rolls-Royce Corniche last December for family-chauffeured jaunts up and down the Pacific Coast. He instructed his family to auction the car after his death and donate the proceeds to AIDS research.

Those who met the sophisticated Halston casually did not see the homespun Roy Frowick in him. His good friends knew better. He was born in Des Moines—to an accountant named James and a mother, Hallie, who was an avid seamstress—and raised in Evansville, Ind. Childhood friends, who knew him as just Roy, remember him as a mischief lover who fabricated fake IDs for his pals while working at International Harvester briefly after high school.

Still his career choice came as no surprise to his classmates. “Roy liked women’s fashions even in high school,” recalls friend Dana Jo Seism, now Mrs. Douglas Holleman of Danville, Ill. “He was interested in well-dressed women.” Fascinated as a child by his grandmother’s hats, Roy Frowick, at age 7, made his first chapeau for his mother with flowers from a neighbor’s garden. After attending Indiana University and the Chicago Art Institute, he designed and sold hats in Chicago’s Ambassador West Hotel, where his first celebrity customer was Fran Allison of the Kukla, Fran and Ollie TV show. He then migrated to New York City, where he landed a job with famed milliner Lilly Daché. By 1958, he was in charge of custom millinery for Bergdorf Goodman, where he received lavish attention from Vogue and where he began selling his own clothing designs eight years later.

In 1968 he left to start his own company, Halston Limited, which quickly attracted such clients as Liz, Liza, Martha Graham, Margaux Hemingway, Betty Ford, Babe Paley and Lauren Bacall. In 1973 Halston sold his business to Norton Simon Inc. for $16 million—a princely price that sent gasps through the industry at the time. Halston stayed on as principal designer and guiding spirit.

His reputation grew as he created comfortable clothes in soft, luxurious fabrics, an antidote to the flamboyant styles of the ’60s that preceded him. His cashmere sweater sets, Ultrasuede shirtdresses, and strapless chiffon gowns rarely required a perfect figure. “His clothes defined ail-American style,” wrote Women’s Wear Daily. In fact his influence is again evident in fashion, where quiet styles, loosely structured and flowing, abound. “Any outfit from Halston is now very ‘today,’ ” says Paloma Picasso, who met him in the mid-’70s. “We are going into more simple shapes and less-decorated clothes.” A prepared statement from Calvin Klein emphasizes Halston’s importance: “I think his contributions to style and clothes will long be remembered. Halston was a real American star and did much to bring international attention to American fashion.”

Usually clad in a turtleneck or tux, he also attracted plenty of attention for his languid, polished mannerisms and un-apologetically dissolute life-style. The music had changed a little, and the barbarians now wore plaid double-knit jackets, but Nero would have felt right at home when Halston held court at Studio 54. At least one party featured a naked woman riding through the premises on a white horse. Accompanied by a loose-knit band of co-conspirators that included Rubell, Warhol, Minnelli, Bianca Jagger and Truman Capote, Halston began to party with a vengeance—and began showing up to work at noon, rather than his usual 8 A.M.

Stories of drug use and homosexual promiscuity abound. One New York man recalls a date with Halston after meeting him at Studio 54 in 1978: “I remember the evening involved massive amounts of cocaine. I went back to his town house at 7 in the morning. We had champagne and more cocaine.” In one entry in the Warhol diaries, Minnelli is quoted as saying to Halston, ” ‘Give me every drug you’ve got.’ So he gave her a bottle of coke, a few sticks of marijuana, a Valium, four Quaaludes, and they were all wrapped in a tiny box…”

Author Steven Gaines, whose biography, Simply Halston, will be published by Putnam next fall, chalks up Halston’s excesses to the times. “Everybody did drugs,” he says. “And in 1978 you went to Studio 54 to get laid—both heterosexuals and gays. I don’t think he got laid more than the next guy or woman. It was a period of wild permissiveness.”

In those days life was “always a giggle” for Halston, his friend Landau says. “One time Halston and Liza and Liz and Henry and Shirlee Fonda were staying at the same hotel in Falls Church, Va., for a Wolf Trap gala. Halston switched the shoes they’d put out to be shined and switched the room-service menus.” Another time Landau, Halston and Warhol accompanied Bianca Jagger to the White House, where she was to meet Chip Carter. “Halston couldn’t believe he was at the White House,” says Landau. “He kept pinching himself. He took a pack of matches that said THE PRESIDENT’S HOUSE for his mother.”

The parties that he gave at his own modern town house, designed by noted architect Paul Rudolph, were as alluring as Gatsby’s. “It was the closest you’d get to a salon in turn-of-the-century Paris,” says Landau. “He was a great choreographer of people. He’d mix Martha Graham and Liza with his accountant or his dentist.”

“He was a very good cook,” adds famed jewelry designer Elsa Peretti, a loyal friend. “And I remember this magic atmosphere of candles and flowers everywhere.”

At the height of his heady popularity, however, some friends saw a change in Halston’s personality. “In the beginning he was great fun,” says China Machado, a former Halston model who is now fashion-and-design editor of Lear’s magazine. “But in the last years he became very grand. If he went somewhere in public he’d choose a table in the corner so that people would have to come up and pay homage to him. Maybe it was because he was the first couturier who asked for a lot of money for his company and got it.” Says former Halston model Jennifer Lee of his Studio 54 period: “He’d gotten grander. Whereas he was always a generous man, very unpretentious, he became consumed by his self-importance.”

That can only have made his fall that much more painful. Halston apparently didn’t realize how much he had given up when he signed his deal with Norton Simon. That corporation had allowed Halston room to follow his creative impulses; when Esmark Inc. acquired Simon in 1983, Halston was horrified to find himself a relatively powerless part of a labyrinthine conglomerate. His cachet took another bashing the same year when he agreed to design clothing for J.C. Penney, prompting upscale Bergdorf’s to drop his haute couture line. He lost more and more control as his company changed hands six times; eventually he was virtually barred from creating anything under his own name. Halston Enterprises is now owned by Revlon, where anonymous designers continue to turn out fashions bearing the Halston label.

Depressed and embittered, Halston stopped designing professionally in 1984, though he drew a handsome salary from Revlon until his death. He became increasingly reclusive, seldom partied and saw only a few good friends. “None of us really knew what happened to him the last few years,” says Grace Mirabella, editor of the magazine that bears her name. “He was paid off and dropped out.” For a man who used to say, “You’re only as good as the people you dress,” professional idleness was torture.

After moving to San Francisco for his final days, Halston, anxious to be remembered at his best and loath to be a burden, declined visits from even his closest friends. The thin duke of New York’s nightlife, a Midwestern boy at heart, sought solace with his family. On good days, at his sister’s home in Santa Rosa, he made chicken soup and beef stew, sunbathed and sketched designs for a new patio. Said Sue Watkins: “I don’t think that he ever lost his spirit for living.”

—Elizabeth Sporkin, Dianna Waggoner and Liz McNeil in San Francisco, John Stark and Toby Kahn in New York City, Jana Wilson in Bloomington, Ind., and bureau reports