Italy has the Agnellis; France has the Arnaults, and patriarch Bernard Arnault is usually in the top three—now and again in pole position—on the league table of the world’s richest men. As well as running an empire that includes Christian Dior, Louis Vuitton, and a range of brands from Clos des Lambrays, a vineyard founded in the 14th century, to Rihanna’s Fenty, he also plays the piano and enjoys knocking a tennis ball about with Roger Federer.

The Arnault family lives up to the image of the products on which Bernard Arnault built his fortune. Delphine Arnault is the poised executive V.P. of Louis Vuitton. Smolderingly good-looking Antoine Arnault, married to model and philanthropist Natalia Vodianova, helms Berluti and Loro Piana. Alexandre bought and runs Rimowa. And, in June, yet another Arnault landed a high-profile job in the family business when 25-year-old Frédéric Arnault was appointed C.E.O. of Tag Heuer.