NEW YORK (CNN) -- Leona Helmsley, who ran her empire of luxurious Manhattan hotels with an iron fist and went to prison for tax fraud, has died, her publicist said Monday.

Leona Helmsley talks with reporters in 2003, when she was taken to court by a former employee.

Helmsley, who was reviled as the "queen of mean," was 87.

She and fourth husband Harry Helmsley owned such sumptuous properties as the Palace Hotel on Madison Avenue, a block from Saint Patrick's Cathedral, the Park Lane and the New York Helmsley.

She died Monday of heart failure at her summer house in Greenwich, Connecticut, publicist Howard J. Rubenstein told CNN.

"Leona was a great businesswoman in her own right who created a tremendous brand and success with Helmsley Hotels and was a wonderful partner and wife to Harry Helmsley," Rubenstein said in a written statement.

"She was extremely generous as a philanthropist and she gave tens of millions of dollars to charity right up until the last months of her life," he added.

Born in Ulster County, New York, and raised in Brooklyn, Leona Helmsley worked as a model and at other part-time jobs.

Her first full-time job was as a secretary in a real estate company specializing in residential sales as Manhattan's condominium craze was beginning to emerge. She moved to Helmsley's company shortly after meeting him in 1969.

She married Harry Helmsley in 1972. He already was a successful real estate magnate, and she helped him amass a commercial and residential real estate empire worth billions.

The couple's holdings included such landmark buildings as 230 Park Avenue and the Empire State Building, as well as the East Side residential complex called Tudor City. Watch how the Helmsleys once had it all »

Adding to her fame was an ad campaign that included her picture and touted her as the "queen" of the empire and a stickler for detail.

She was tried in 1989 for tax evasion, but poor health spared her husband from facing charges. The sensational trial included testimony from disgruntled employees who said she terrorized the help at her homes and hotels.

A former housekeeper testified that she heard Helmsley say: "We don't pay taxes. Only the little people pay taxes."

She denied having said it, but the words followed her the rest of her life.

After serving her prison sentence, and following her husband's death in 1997, she became chief executive officer of Helmsley Enterprises and managed the real estate and hotel portfolio, but with a far lower profile than the one she had cultivated in the 1980s.

Leona Helmsley's charitable activities included a $25 million gift to New York Presbyterian Hospital, $5 million to Katrina relief and $5 million to help the families of firefighters after the September 11, 2001, terrorist attacks.

In the late 1990s, she gave millions of dollars to help rebuild African-American churches that had been burned in the South.

Helmsley is survived by her brother, Alvin Rosenthal, four grandchildren and 12 great grandchildren. Funeral arrangements have not been made public. E-mail to a friend

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