Their stores account for 10% of French households' spending every year and their group owns popular retail and commercial names in France such as Auchan supermarkets, Leroy Merlin DIY stores, Flunch restaurants, Norauto car accessory outlets, Décathlon sports shops and Kiabi clothing stores. The group also runs hugely lucrative operations in Russia, China and other countries. But the people who own it, the Mulliez family, are virtually unknown in France, and shun all press coverage and publicity. Now, against the wishes of the head of the secretive Mulliez dynasty, a book has been published charting how 650 descendants of the group’s founders today preside over a rich and powerful global retail empire. Dan Israel reports.