No Regrets: The Life of Marietta Tree.

By Caroline Seebohm Simon & Schuster, $27.50

Marietta Tree was the quintessential WNSP--a glamorous, freewheeling spirit born into the stern, judgmental Peabody clan, one of Boston's finest families. Nee Mary Endicott, Marietta was the rebellious only daughter of a reserved Episcopal minister, a parsimonious and austere mother, and most importantly, the granddaughter of the revered Rector of Groton. An effervescent, leggy blonde, Marietta was an accomplished flirt and irresistible to men from an early age. At Groton she created havoc when she appeared in the dining room or at the playing fields, and in her later years she remained the center of attention, pursued and surrounded by admirers and beaux.

No Regrets, which chronicles Marietta's life, is packed with famous names, places, parties, and political intrigue and reads like a Who's Who of the 20th century. It should have been the stuff of fairy tales, but unfortunately it is not. With access to family and close friends, letters, diaries, and engagement books, author Caroline Seebohm pierces the mystique surrounding Marietta to reveal a troubled woman who led a hidden life: clandestine love affairs, estrangement from her four brothers and two daughters, guilt and anxiety over a loveless childhood, emotional isolation, and two failed marriages. To avoid reality, Marietta filled her time with frenzied activity, social and political, and when she at last succumbed to cancer in 1991, at the age of 74, she was filled with remorse as she tried to retrieve her relationships and re-spool the threads of her past. Seebohm's book, therefore, although extremely well written, is wrongly titled. With Regret would be much closer to the truth.

Unlike many of her rich, spoiled friends, Marietta grew up in a strict and frugal household. Her mother was appalled when a guest once asked for two lumps of sugar. Although the Peabodys were socially supreme, they were not well-off and frequently depended on wealthy relatives. As a result, saving face and keeping up a good front formed the core of Marietta's personality and she retreated behind a mask of impervious charm. Unable to accompany friends on expensive trips and forced to wear the same evening gown to opulent debutante balls put a crimp in Marietta's adolescence, but she rarely complained and set her sights on financial freedom and a career in the Foreign Service. She was later crushed to discover she could enter only by marrying into it.

At 19, Marietta was prescient. When asked to predict her own future, she wrote down, "Parties, people, and politics." Her first husband, Desmond FitzGerald, a proper New York lawyer, introduced the beautiful aristocrat to Manhattan's haute monde and she discovered the world she craved. By day, Marietta worked at Life as a fact checker, but at night, she donned her signature black-mesh stockings and went partying with the Astors, Paleys, and Warburgs. She described those years as "a fever of happiness"

In 1945, while FitzGerald was away at war, Marietta embarked on a passionate affair with film director John Huston and "went head over heels" The pair contemplated marriage, but Marietta ditched Huston after meeting Ronald Tree, a bisexual but wealthy and urbane Anglo-American with magnificent homes in England and Barbados. He was 20 years her senior, and when they decided to marry, Marietta's parents were horrified--there had never been a divorce in the Peabody clan. Despite their condemnation, Marietta pressed on, separating herself from her family to attain a stellar role in international society.

With Tree's money behind her, Marietta established an eclectic salon in New York and plunged into Democratic politics, becoming an ardent supporter of presidential contender Adlai Stevenson. The two began a romance in 1952, which placed Marietta at the pinnacle of power and led to her appointment to the U.N.'s Human Rights Commission. The affair lasted until 1965 when Stevenson collapsed and died on a London street corner with Marietta at his side. (Although Stevenson was rumored to be homosexual, the Washington cognoscenti were aware of his involvement with a number of high-profile women. Among the romances that Seebohm details are his dalliances with philanthropist Mary Lasker; publisher Alicia Patterson Guggenheim; and socialites Brooke Astor, to whom he once proposed, and Ruth Field, the widow of Marshall Field.)

Stevenson was a Casanova of the billet-doux, and much of his love life was conducted by letter. Marietta and Stevenson developed code names for each other--Mr. and Mrs. Johnson, and Mr. and Mrs. Richardson--and arranged trysting spots at various friends' houses that they considered "safe." But throughout his affair with Marietta, Stevenson could not resist the pursuit of other women, artfully seducing them with endearing notes, apologies of neglect, and endless charm. To keep Marietta on edge, he frequently disclosed his other amorous encounters, and stockpiled in a drawer by his bed a number of poems and meditations of love that he would send, and receive, from various females. He also saved some of his paramours' love letters, which he called "tender bits."

After Stevenson's death, Marietta's personal life was in shambles. She was alienated from her daughters, model Penelope Tree and author Frances "Frankie" FitzGerald, and all but separated from her husband. Over the years, due to British taxes, Ronald Tree's fortune had dwindled, and when he died in 1976 Marietta was forced to sell much of her property and alter her lavish lifestyle. But she was far from a damsel in distress. There were plenty of well-placed suitors ready to offer aid and advice, and Marietta was already deeply attached to another man: Richard Llewelyn Davies, an English architect and urban planner. Although Davies was married, they became inseparable and Marietta helped to finance his business, hoping he would divorce. But he died suddenly in 1978 and Marietta found herself responsible for some of his debts. By this time, however, she was financially secure as the result of solid investments and calling in all her chips. Through friends and connections she wangled lucrative directorships on several corporate boards including CBS, Pan Am, and Lend Lease of Australia. The fees she received enabled her to retain her high-octane lifestyle, to sail blithely through the hectic '80s with the same elan she had displayed during her heady, early years. Only this time the names and players were different: Trump, Guttfreund, and Steinberg--the flashy new rich.

Discovering she had breast cancer at 72, Marietta underwent a mastectomy, consulting her crammed engagement book to squeeze in post-op chemotherapy between trips and social obligations. Refusing to acknowledge her sickness or to limit her frantic schedule, she told no one except her daughter Frankie, who was sworn to secrecy. When unable to attend a benefit or event, she dissembled, claiming she had the flu, and continued making dates well into the future. Not even her swain, Eben Pyne, ever knew she had undergone surgery and was terminally ill.

During this time, Marietta tried to repair ruptured family links. But for several members who were kept in the dark about her illness and feared rejection, these efforts came too late. Sadly, she had achieved her goal and created a fool-proof exterior. Her death was her ultimate cover-up. In a final tribute, her daughters taped her 1991 red leather calendar to the box containing her ashes. It was an ironic gesture that Marietta would have enjoyed. As she once told a childhood chum, "Always look as if you're having a wonderful time."

Sandra McElwaine is a Washington-based journalist.