LVMH

Delphine Arnault, 32, is Bernard Arnault’s oldest child and one of LVMH’s largest shareholders. She was a Christian Lacroix salesgirl at age 18, then worked briefly at McKinsey before returning to the $55 billion conglomerate and working her way up through the ranks at Dior. She has long been seen as her father’s most likely successor, and her recent marriage to Italian wine heir Alessandro Vallarino Gancia doesn’t seem to have changed her course: She sits on the boards of LVMH and Loewe and joined Pucci’s board this summer.

While his sister spent her twenties at LVMH, Antoine Arnault, 29, started Domainoo, an internet company that auctions domain names, with some pals from Montreal (and plenty of startup capital from Dad) when he was 23. He is now director of communications for Louis Vuitton. In May 2006, he was named an LVMH board member—his sister had joined the board several years earlier—a sign that his star is ascending.

Bulgari

C.E.O. Francesco Trapani, 50, was only 27 when he took over Bulgari, then just a high-end Italian jewelry company. It took him more than a decade to persuade his uncles—Paolo and Nicola Bulgari, chairman and vice-chairman, respectively—to expand the brand to include fragrances, accessories, and, in 2000, hotels. Analysts fret that such extensions could dilute the Bulgari name and eventually hurt the core gem business, but Trapani defends them as useful image builders. The future strength of the $4.6 billion company, he has hinted, lies in the Middle East, where sales rose 9 percent last year.

Hermès

Longtime C.E.O. Jean-Louis Dumas, great-great-grandson of the company’s founder, broke the 167-year chain of family control last year by handing over the store to outsider Patrick Thomas, 60, previously the managing director of Hermès International in Paris. But the company’s profits haven’t increased as much as its peers’ during the luxury industry’s current boom. Now, its stock price suddenly seems inflated, and Thomas has been under fire. Dumas’ son, Pierre-Alexis, 40, and niece Pascale Mussard, 52, stayed on as co-artistic directors after the new C.E.O. took over, and investors are looking to the duo’s designs to lift the venerable label out of its doldrums. Despite all this grim news, the company is constantly rumored to be a target for acquisition—a transaction that would be complicated by the number of family members involved. About 60 relatives own chunks of the $11 billion firm, but none has more than 5 percent.