When in New York, the Wertheimers lunch most every day in their corporate dining room, enjoying a light menu -- ''soup in the winter, seafood in the summer,'' Alain once said -- often accompanied by a bottle of Rausan-Ségla, their deuxieme cru Bordeaux, in a crystal decanter. They prefer to entertain at home, dinners of 12 or so ''with all the footmen and other Continental accoutrements,''one invitee recalls. When they do give to charities, it is to those that personally interest them, like the Game Conservancy Trust in Britain or Action Innocence (against child pornography on the Internet) and an orphanage in Santo Domingo, two projects run by Gérard's wife, Valérie, a former nurse.

And they work -- Alain in New York, Gérard in Geneva -- quietly and diligently managing the family empire. In the 28 years since Alain took over the helm of Chanel and the family's original holding, Bourjois Cosmetics, from his father, Jacques, the portfolio has grown to include the gun makers Holland & Holland; Frédéric Fekkai beauty salons; Erès, maker of bathing suits and lingerie; G & F Chatelain, the watchmakers; and until three years ago, the Isaac Mizrahi Company. ''We're in the business of selling pleasure,'' Alain explained to Wine Spectator. ''We don't sell handbags or haute couture. We sell dreams.''

The Wertheimers' obsession with secrecy is in part cultural: the French believe there is no reason to reveal one's private life in the pursuit of business goals. But their silence is also a professional ploy. Unlike other limelight-seeking luxury titans like Bernard Arnault, the owner of LVMH Moët Hennessy Louis Vuitton, and Domenico De Sole, the chief executive of Gucci Group, the Wertheimers prefer to remain anonymous and let their brands be the stars. It is an odd way of doing business in an industry that has increasingly turned its business barons into celebrities. But this seems to suit them fine, and it has been the way they have conducted their businesses since their grandfather Pierre first negotiated a contract with Coco Chanel in 1924.

The Wertheimers, whose roots date to medieval Germany, arrived in Paris when Pierre's father, Ernest, left Alsace during the Franco-Prussian war. In the 1870's, Ernest invested in Bourjois, a theatrical makeup company, which by the 1920's his sons, Pierre and Paul, had turned into the biggest cosmetics and fragrance business in France.

Pierre was also an avid horseman who began one of the world's great racing dynasties. The Wertheimers' first winner was in 1911; their first champion was Epinard, in the early 20's. Pierre's greatest success came in 1956, when his horse Lavandin won the Epsom Derby. Today, Gérard oversees the family's horse stock, which in 1995 included 120 horses in Chantilly, a few in California and 70 broodmares divided between Kentucky and the Haras de Saint-Léonard-La-Barbérie, their stud farm in Normandy, with Kentucky-style barns and a small chateau moved brick by brick from l'Orne.

The horses are an important part of the Wertheimer story because it was at the races that Pierre met Coco Chanel. Born in a poorhouse and raised in an orphanage, Chanel was a courtesan and the milliner for the mondaine, with shops in Paris, Deauville and Biarritz. In 1922, she and Ernest Beaux, a perfumer from Grasse, created the scent known as No. 5, said to be named for Chanel's lucky number. The perfume was an instant hit with Chanel's customers, but it was made in limited amounts in Beaux's laboratories. Théophile Bader, the founder of the department store Galeries Lafayette, wanted to sell No. 5, so he introduced Chanel to his friend Pierre Wertheimer at the Longchamp racetrack outside Paris.

In 1924, the trio negotiated a deal that incorporated Les Parfums Chanel. Wertheimer would make No. 5 in his Bourjois factory and receive 70 percent of the profits. Bader earned 20 percent as a finder's fee. And Chanel herself received a mere 10 percent. Feeling she had been cheated, Chanel filed lawsuit after lawsuit, trying to get more control and more of the profits. By 1928, according to Axel Madsen in the biography ''Chanel: A Woman of Her Own,'' the Wertheimers had a lawyer on their staff who dealt solely with Chanel.