When the celebrated French antiques dealer Didier Aaron died of a brain tumor in Paris on January 3 at age 85, the world bid adieu not only to the doyen of the powerful postwar Parisian seigneurs of 18th-century furniture but also to a unique figure in the French art world. Aaron was admired as much for his entrepreneurial spirit as for his connoisseur’s eye. He was the first antiquaire to open a decoration department, with the Paris decorator Alain Demachy in the 1960s, and the first to establish branches in New York, London and Los Angeles (although this last has since closed), creating an empire that is now directed by his son Hervé, who joined the company in 1975.

The elder Aaron also had a genius for discovering fresh talent. "Working with such bright young people is what amuses me," he said in a 2001 interview, referring to Hervé and his curatorial team at the gallery. This group included the famed Paris decorator Jacques Grange, the noted 18th-century scholar Bill G. B. Pallot and the fine-art expert Bruno Desmarest, who today head up, respectively, the departments of decoration, furniture and art objects, and paintings and drawings.

"Didier hired me in 1968 when I was 23," Grange recalls, "and he quickly propelled me into decoration, giving me the homes of his clients to do. He did more than jump-start my career." Pallot was also recruited at a tender age, 22, in 1987, "when I had the theoretical knowledge but not the practical expertise," he says, adding that Aaron taught him about eclectic taste: "In addition to the pure Parisian 18th-century furniture of great quality, such as Reisener, we could mix in the high-end pieces from Portugal, Spain, England and elsewhere at a time when no Parisian was looking at foreign furniture."

"Aaron was one of the giants, a great connoisseur and one of the most active in the métier," says François Curiel, the chairman of Christie’s Europe. "He was an antiquaire with a capital A. He had an eye for everything: art, furniture and objects from the Renaissance to the 21st century."

This eclecticism was displayed in Aaron’s own Paris apartment. There, says Pallot, "an armchair by the artist Arman might be combined with a 17th-century Dutch cabinet, a Louis XIV Boulle desk and 19th-century German pictures," set against red-lacquered walls, in the dining room, or caramel-hued boiseries, in the library.

Curiel, who knew the dealer well, says he had " a strong personality and a brusque manner but a heart of gold." Pallot confirms Aaron’s generosity, exemplified in his system of profit sharing. "Didier said, ‘Make me money, and you will make money too,’ " Pallot recalls. "And it was true."

Aaron’s double vocation, as antiquaire/entrepreneur, might have had familial roots. He was born — in April 27, 1923, in Paris — to a stockbroker, Raoul, and Jeanne, who in addition to running a shop that sold 18th-century furniture and Asian antiques, also had a coterie of artistic friends, including the painter Marie Laurencin and the Art Deco designer Jean-Michel Frank. The young Didier studied art history and law, and, with the onset of World War II, joined the French Resistance at age 18, in the Vercors, a mountainous region southwest of Grenoble. From there he went to Nice, where he worked with his brother for the Free French forces as an information liaison with the United States Army in 1944.

After the war, Aaron returned to Paris and took over his mother’s business. In 1946 he opened his own gallery, in the 16th arrondissement, relocating in 1988 to the Faubourg Saint-Honoré, where he was soon joined by other dealers. In the 1980s, Aaron was one of the first to look to Asia as a new market.

In another innovation, he expanded abroad, first to New York, in 1977. "He bought the gallery building [on East 67th Street] near Madison Avenue at just the right time, when the dollar was low," recounts his longtime friend the French antiquaire Jacques Perrin. "He had a real business sense." Aaron became an ambassador of French taste in the U.S. At times, American collectors and museums accounted for 70 percent of the firm’s sales. Aaron also acted as a unifying force within the Parisian antiques world, founding the Antiquaires à Paris, a small group of top dealers.