(FORTUNE Magazine) – For minting ten-figure treasures, France -- with one billionairess and a single billionaire clan -- has long been the industrial world's poor cousin. Among the disincentives: sky-high taxes, state control of major industries, and an abiding national disdain for the hot pursuit of wealth. It was the French, after all, who supplied the English language with its two most caustic pejoratives for new money, ''parvenu'' and ''nouveau riche.'' That situation is changing fast, thanks to the free-market tonic of deregulation and tax cuts, coupled with a booming Bourse and a cultural revolution that is making folk heroes of top businessmen. Last winter the business magazine L'Expansion found that 55 of France's 100 richest people are self-made men, including publisher Robert Hersant, ($400 million), couturier Pierre Cardin, and construction magnate Francis Bouygues (both over $300 million). France's billionaires, too, are nouveau, at least by French standards, having come by their money as heirs of two 20th-century entrepreneurs. Marcel Dassault got plenty of government help in leading the nation's ambitious postwar drive in military aviation. A diminutive dynamo who sported a tiny mustache, thick smoked glasses, and a felt fedora, Dassault built Avions Marcel Dassault-Breguet Aviation into one of the world's leading makers of military aircraft (1986 sales: $2.6 billion), turning out a series of sophisticated, hot-selling fighters. Dassault, who died last year at 94, left an after-tax estate of $1.8 billion to his widow, Madeleine, 86, and sons Serge, 62, and Claude, a recluse whose age is a family secret. Marcel met Madeleine in 1916, when he shared a workshop with her father, a furniture manufacturer who gave the young man the slab of walnut he used to carve a revolutionary new propeller. Married at 18, Madame Dassault spent her life as a housewife, taking time to play bridge and classical piano. In 1964 she made headlines as the victim of a brief kidnapping. Rescued unharmed by two rural policemen, she posed for photographs toasting the beaming gendarmes with champagne. Serge, a moon-faced extrovert who puffs Cuban cigars, founded a now-defunct Libertarian-style political party and regularly conducts flamboyant but unsuccessful campaigns for parliament. Trained as an aeronautical engineer, he left a top post at his father's company in 1967 and spent the next 19 years building Electronique Serge Dassault into a thriving producer of military electronics (1986 sales: $612 million). But now that the plane company's oil- producing customers are short on cash, Serge has returned as chief executive to protect his family's 49.7% stake. Working 14 hours a day, he hopes to win fresh business outfitting old planes with new weapons systems. The dizzying success of cosmetics producer L'Oreal has made Liliane Bettencourt ($1.5 billion) France's wealthiest individual. Her father, Eugene Schueller, invented the first chemical hair dye in his kitchen sink in 1907, and then launched L'Oreal by cycling around Paris to peddle his wares to hair salons. During the 1940s Bettencourt, a willowy beauty with auburn hair, worked for her father in a variety of jobs, among them trying out dyes on volunteers. Apart from that stint, she has taken no active role in L'Oreal. But she has played her passive role to perfection by putting total confidence in Francois Dalle, her father's protege. Dalle, who ran L'Oreal from 1957 to 1984 and still heads strategic planning, built it into the largest beauty products company in the world -- and helped boost the value of Bettencourt's shares from relative peanuts to almost $1 billion. Bettencourt and her husband, Andre, a former Gaullist minister, live in a sumptuous townhouse near Paris filled with masterpieces of art deco furniture. They have one child, a married daughter, Francoise. Following Dalle's advice to diversify, Bettencourt in 1974 exchanged a 25% stake in L'Oreal for some 4% of Nestle, an investment that has flourished. Unlike Serge Dassault, whose performance will determine whether the family wealth grows, Bettencourt seems likely to keep getting richer just by staying judiciously in the background.