Ambroise Vollard (1867-1939); pioneer art dealer, patron, and publisher who played a key role in promoting and shaping the careers of many leading artists during the late 19th and early 20th centuries….
"Vollard's genius lay in his ability to identify undiscovered talent," commented Philippe de Montebello, Director of The Metropolitan Museum of Art. "That Cézanne, Gauguin, Van Gogh, and many others are household names today is in large part due to Vollard's early promotion of their work.
Vollard was a legend in his own lifetime…. He had a unique – some thought eccentric – approach to selling art, frequently dozing in his gallery, making a point of not showing his clients what they asked to see, and concealing most of his paintings behind a divider at the back of his shop.
(https://www.metmuseum.org/press/exhibitions/2006/c%C3%A9zanne-to-picasso--ambroise-vollard-patron-of-the-avantgarde)