The Duchess of Windsor, the coolly elegant American divorcee for whom King Edward VIII gave up the British throne, launching a love story that became one of the enduring legends of the 20th century, died yesterday at her home in Paris. She was 89.

Her death was announced in London by Buckingham Palace. Sources said she died of bronchial pneumonia.

She was Wallis Warfield Simpson, 40 years old and awaiting the final decree of her second divorce, when, on Dec. 11, 1936, Edward broadcast a farewell to his people and pronounced these famous words:

"You must believe me when I tell you that I have found it impossible to carry out the heavy burden of responsibility and to discharge my duties as king as I would wish to do without the help and support of the woman I love."

Mrs. Simpson was staying at the house of friends outside Cannes on the French Riviera when Edward spoke and she gave this description in her memoirs, "The Heart Has Its Reasons:"

"As the moment approached . . . everyone . . . gathered around the radio in the sitting room. [Edward's] voice came out of the loudspeaker calmly, movingly. I was lying on the sofa with my hands over my eyes, trying to hide my tears. After he finished, the others quietly went away and left me alone. I lay there for a long time before I could control myself enough to walk through the house and go upstairs to my room."

On June 3, 1937, at the Chateau de Cande in the Loire Valley in France, His Royal Highness Prince Edward, Duke of Windsor, and Mrs. Simpson, the former Bessiewallis Warfield of Baltimore, were married. So great was the interest in the duke and duchess that they became one of the most exhaustively reported stories of modern times -- and almost always they were cast as the principals in a tale of unblemished love.

Indeed, for Edward the crown was less important than marriage. But for the duchess, the status conferred by the crown was more important than the man, and by all accounts she could not give him the affection he required. "You have no idea how hard it is," she once said, "to live out a great romance."

"The Windsor Story," by Charles J.V. Murphy and J. Bryan III, two authors who helped the Windsors write their memoirs, portrays the former king as a man utterly dominated by his wife, who often treated him with contempt.

They describe her five-year relationship with Woolworth heir James Paul (Jimmy) Donahue Jr., a playboy and homosexual. When the duke complained, she reportedly said, "What could possibly be more harmless? Everybody knows what Jimmy is. Why, his friends call me the Queen of the Fairies."

They relate that the duchess became annoyed at the duke for leaving some papers on a table, prompting him to say, "Darling, are you going to send me to bed in tears again tonight?"

When his father, King George V, died in January 1936, Prince Edward Albert Christian George Andrew Patrick David was proclaimed Edward VIII "by the grace of God, of Great Britain, Ireland, and the British Dominions beyond the Seas, King, Defender of the Faith, Emperor of India . . . . "

With the abdication, he became a private citizen. In Britain, his decision to depart was widely regarded as a failure of duty to the empire and a refusal to understand his role as a constitutional monarch.

Except for five years during World War II, when he was governor of the Bahamas, he never again held public office. No government offered one.

The Windsors had great wealth and celebrity and much leisure. Their main residence after the war was a house in the Bois de Boulogne, a property of the City of Paris for which they paid only nominal rent. For several years, they owned a converted mill outside the French capital, the Moulin de Tuileries. They were exempted from French income taxes.

Whatever they did, from an ill-advised trip to Germany and a call on Hitler before the war -- the duke was notably sympathetic to many of the Nazi leader's aims -- to their later wanderings between New York, Biarritz, Paris and various resorts, interest in them never flagged.

News reports included such trivia as their luggage (usually about 30 pieces). Their clothes and their parties were famous. Their footmen wore livery. The duke had his coats made in London and his pants made in New York. He invented the Windsor tie knot and introduced the double-breasted dinner jacket.

The duchess had her hair done daily and for years was listed among the 10 best-dressed women in the world. She had an extraordinary collection of jewelry. The duke liked money, golf and gardening. They both liked dogs.

In her book, the duchess said she enjoyed the privileges Edward commanded.

"His slightest wish seemed always to be translated instantly into the most impressive kind of reality," she wrote. "Trains were held; yachts materialized; the best suites in the finest hotels were flung open; airplanes stood waiting. What impressed me most of all was how all this could be brought to pass without apparent effort."

As to why she persisted in the relationship even to Edward's abdication, she wrote:

"The answer to that hinges on a misconception on my part and, I suppose, the fundamental inability of a woman to go against the urgent wishes of the man she loves. The misconception sprang from my failure to understand the king's true position in the constitutional system . . . . Nothing that I had seen had made me appreciate how vulnerable the king really was, how little power he could actually command, how little his wishes really counted for against those of his ministers and Parliament."

Nor did she or the duke understand the royal family's refusal to allow her to be addressed officially as "her royal highness." In her definitive biography, "Edward VIII," Lady Frances Donaldson states the decision to withhold the title was part of a plan by George VI, Edward's oldest brother and successor, and his government to keep the ex-king out of official life in Britain.

Mrs. Simpson was born at Blue Ridge Summit, Pa., on June 19, 1896. Her parents, Teackle Wallis Warfield and the former Alice Montague of Virginia, had gone there to escape the summer heat of Baltimore.

Teackle Warfield died when his daughter was only a few months old, leaving his family with little money. The child was educated by an uncle, Solomon Warfield, and she made her debut at the Bachelor's Cotillion in Baltimore. She was 20 when she married Earl Winfield Spencer Jr., a pilot in the Navy. She said she realized this was a mistake when he drank and locked her in her room.

She was divorced from Spencer in 1927. A year later she married Ernest Simpson, an Englishman whose mother had been an American, and he took her to England.

The duke said in his memoirs that he and Mrs. Simpson met at a fox hunting party in Leicestershire, England, in the winter of 1930-1931. They were introduced by his favorite of that time, Lady Thelma Furness, another American.

In 1933, Edward gave Mrs. Simpson a birthday party and she and her husband became frequent guests at Fort Belvedere, Edward's house near London. In the summer of 1934, Mrs. Simpson alone was the prince's guest aboard the yacht "Rosaura" in the Mediterranean.

"Perhaps," she wrote, "it was during these evenings off the Spanish coast that we crossed the line that marks the indefinable boundary between friendship and love. Perhaps it was one evening strolling on the beach at Formentor in Majorca. How can a woman ever really know?"

In the summer of 1936, the king and Mrs. Simpson cruised the Dalmatian coast and the Greek Islands aboard the yacht "Nahlin." Few holidays in history have attracted more attention. Everywhere they were greeted by cheering crowds. The press was out in force.

All the press, that is, but the British press. In those days British newspapers confined their coverage of the "royals" to formal announcements of such matters as palace guest lists. At the suggestion of Lord Beaverbrook, the owner of the Daily Express, to whom the king had appealed, British publishers agreed informally to keep mum about Edward and his friend. So ordinary Britons had no idea that their king was in love with another man's wife.

Of course, informed opinion knew about it. It was not the relationship that scandalized -- mistresses are as old as monarchies -- but the fact that the king flaunted it in public. No one, including Stanley Baldwin, the prime minister, contemplated marriage. For the fact was that Mrs. Simpson already had a husband.

In October 1936, however, she obtained a decree of divorce that would become final six months later. Baldwin asked Edward to have the court action stopped.

"I believe I know how to interpret the minds of my own people," he told the king. "And I say that although it is true that standards are lower since the war, it only leads people to expect a higher standard from their king."

Edward said that Mrs. Simpson was "the only woman in the world and I cannot live without her."

Under British law, the wife of the king is the queen. So Edward asked for special legislation that would allow Mrs. Simpson to be his wife but not the queen. He thus provided the occasion for the end of his reign. For if the government refused he was bound by the constitution to accept that decision. That would leave him to choose between the crown and marriage to a divorcee.

It was not until 1966 that Queen Elizabeth II received the duchess. It was at the unveiling of a plaque in memory of Queen Mary, the duke's mother. It was not until the duke's death in 1972 that the duchess was a guest at Buckingham Palace.

Thereafter she lived alone and as the years passed infirmities increased. In 1973, she broke a hip. In 1977, she had a stomach hemorrhage and underwent surgery. She had been bedridden since then.

The Buckingham Palace announcement said she would be buried next to her husband in Frogmore Garden at Windsor Castle.

In the Moulin de Tuileries, the old mill outside Paris where the duke had gardened and his wife had practiced her considerable skill in interior decoration, the duchess had these words inscribed on a wall:

"I am not the miller's daughter, but I have been through the mill."