"INHERITED WEALTH is a real handicap to happiness," wrote William K. Vanderbilt, a good-natured man who had the misfortune to have inherited $90 million. Yet for his daughter Consuelo, the mother fate handed her was an even greater handicap than all that money. Alva Smith was an impenitently ambitious daughter of the old south who fictionalized her tradesman father into a Virginia gentlemen, transformed her life as a poor refugee in France during the Civil War into "private education abroad," and buried the facts of her first years in Manhattan spent in her mother's boarding house. She married Willie Vanderbilt, grandson of the richest man in America, and in 1877 gave birth to a daughter she was determined should be a real princess.,

The future noblewoman's childhood was everything to create a depressed self-punitive cripple, and it largely succeeded. Consuelo was separated from other children by her elaborate costumes and schooling governesses, tovernesses, her wistfully charming looks were ridiculed, she was whipped on the legs with a riding crop when she timidly showed spirit, and was buckled into an orthopedic corset to insure a queenly carriage that marked her for life. The Vanderbilts were rich but socially unassuming. Alva changed that when she hired Richard Morris Hunt to build a $3-million Renaissance palace on Fifth Avenue. It was neither Louis Sullivan's nor Consuelo's idea of a home. Her father was relegated to a little room and she to a tower reached by a fearsome dark staircase. Alva's first ball in the new house rudely unseated the queen of New York society, Mrs. Astor, whose daughters made a brave show with battery-powered light bulbs in their hair. When Alva's indulgent father-in-law realized that her ambitions were running ahead of Willie's income, he made him president of a railroad and slipped him $5 million in bonds, and on his death left him another $65 million. Alva went on building: a villa on Long Island, an $11-million Newport cottage, modeled on the Grand Trianon, and a large, uncomfortable yacht - the Alva, of course. "I know of no profession, art or trade that women are working in today," she declared, "as taxing on mental resources as being a leader of society."

Consuelo grew up an anxious, timorous, introverted bookworm who dared no opinions. "I do the thinking," said Alva. "You do as you are told." Little wonder that when Consuelo first fell in love, Alva jeered at her feelings, intercepted letters and sent the young man packing. (He was highly eligible but just an American.) When Consuelo threatened to elope, her mother swore she would shoot her sweetheart, and after this awesome threat, staged a phony heart attack that brought the credulous girl to heel.

Meantime Alva was trail-blazing, asking the long-suffering Willie for a divorce and boasting that whereas before her bold step society women dared not ask, now they were clamoring for divorces. She made no connection between her own failed marriage and the alliance she proposed to force on Consuelo with the Duke of Marlborough, not quite a prince, but possessor of a great dilapidated palace and not much money. He coolly agreed to the match in exchange for $100,000 a year.

During her honeymoonConsuelo would be doctor predicted the miserable Consuelo would be dead within months, but in England she improved. Blenheim couldn't be compared in comfort to Alva's houses, but Consuelo found a friend in her husband's cousin Winston Churchill and liked her spirited mother-in-law, another trail-blazing divorcee. But her husband, like Alva, was more lavish with fault-finding than praise, and at 8-course dinners a deux they faced each other in gloomy silence.

Her social role she played handsomely, rigidly ordered and hollow though it was, and found an escape through a back gate that led into a tiny village. Here she visited the poor, read the Bible to a blind woman, and pressed gifts on anyone with a hard luck story. Two sons were born to her, a future duke and a "spare." She saw little of them: the nanny-and-school system swallowed them up, leaving her to play Lady Bountiful to other people's children. While the duke showered Vanderbilt money on Blenheim's gardens, Consuelo read new novels (James, Wharton, and Wells), spent some of her own $100,000 a year on the local poor and more on herself - precious furniture, rugs, porcelain, and self-portraits, including a cold, ungainly Sargent of both Marlboroughs and their sons, in which she towers over her short, grim husband.

By the time she was 28 her bickering marriage was finished and she was incurably deaf. In 1905 a formal separation agreement was signed, but without grounds - adultery - there could be no divorce. For the next 15 years she tagged along in the footsteps of her prepotent mother, now Mrs. Oliver Belmont. Alva, having renounced her social throne, had become a militant liberal, bailing out The Masses when it was in trouble, briefly publishing a satirical magazine whose main job was to pillory the Vanderbilts and throwing most of her formidable energy and money into getting women's votes. (It was she who once advised someone to call on God: "She will help you.") She even wrote lyrics for a suffragette operetta with music by Elsa Maxwell. Consuelo lacked her mother's convictions and flair, but she fought for minimum wages for women, sponsored a conference on eugenics, started a sewing factory, gave uplifting talks in the slums on such subjects as flowers as emblems of ideals, raised money for a hospital during the war and finally won a seat on the London County Council. Socialism, however, she thought extreme; there were no problems that good fellowship could not solve.

If money was never short - hardly!, her father gave her $15 million more in anticipation of his death - love was. She had plenty of admirers, but the temperament of a prig. In this she was the antithesis of her warm-blooded aunt by marriage, Jennie Churchill. But when at last a French aeronaut, Col. Jacques Balsan, turned up, she threw over good deeds. A divorce was arranged with the duke - an elaborate charade - and on the Fourth of July, 1921, she married for love. Later an annulment of the Marlborough marriage was arranged. One of the most persuasive witnesses was the original villain. "I have always had absolute power over my daughter," Alva confessed. "When I issued an order nobody discussed it. I therefore did not beg but ordered her to marry the duke."

The remainder of Consuelo's blameless life was lived well in France and the U.S. When she died in 1964, she left only $2 million of all the vast sums that had come to her. Plenty had gone to Rolls Royce and perfect houses, but she had the itch to be "useful" too - a word she valued - and she was remembered kindly when her remains were buried in the village outside Blenheim's back gate.

James Brough also wrote Elliott Roosevelt's account of his parents' marriage and a book called Margaret: The Tragic Princess. The heroine of Consuelo comes across as earnest, nothing if not wistful, and a mite bitchy, ticking off Margot Asquith as a "clamorous outsider" and Clementine Churchill as "really a stupid woman." The Duke of Marlborough is a stubbornly opaque personality. His nickname "Sunny" (short for one of his titles) hardly describes the cross-looking man seen in the photographs. In spite of his filial devotion to Blenheim, his readiness to make a deal with the Vanderbilts without any more human regard for Consuelo than her mother exhibited, condemns him. And as for Alva, the irony of her flight for woman suffrage when she had utterly deprived her daughter of all rights is on the egregious scale of her other deeds. CAPTION: Picture, Jacket photo of Consuelo Vanderbilt (1902)