In 1977, André Mentzelopoulos was a man ahead of his time. The wines of Bordeaux had just gone through a serious economic crisis and scandal ; investors were not interested in classified growths, and the owners did not have the means to invest in their lands.

André Mentzelopoulos sensed the opportunity and invested massively without expecting any immediate return in a market that was still depressed and a few years away from the new golden age for Bordeaux at the end of the 20th century. He made spectacular moves: in the vineyard, where better drainage was introduced and new plantations made; in the cellars, under the supervision of the oenologist Emile Peynaud, Pavillon Rouge was reintroduced with a considerable increase in selection ; new oak barrels were used to age the wine, plans were drawn up for the first great cellar in the region to be built underground (a technical feat), and Pavillon Blanc was redefined. In the château and its outbuildings, under the supervision of the inspectors for Historic Monuments (Margaux is a classified monument), the reconstitution of the architectural heritage and the renovation of the interior were carried out. All of this was done with deep respect for the existing structures and with the determined aim of allowing the terroir to express its fabulous qualities. The 1978 vintage at Château Margaux was acclaimed immediately as an outstanding success, the proof of the efficiency and sheer scale of work achieved by André Mentzelopoulos. He died in 1980, too young and too quickly for him to be able to enjoy the revival of his Château Margaux. No owner has played such a profound rôle, and in such a short time, in the long history of Château Margaux.