Born in Brussels, Gambart was the dominant art dealer in Britain from 1840 through his retirement from the trade in 1871. He originally went to England as a representative of the Parisian print publishers Goupil and ultimately set up his own business. He was best known to the United States public with his exhibition of a single painting, Rosa Bonheur's Le marché aux chevaux, which toured the country in 1857-1858 and for which admission was charged. Gambart married three times but had no children. After his retirement c. 1870, his business was carried on to some extent by his nephews, Charles Deschamps and Léon Lefevre, who with his partner Pilgeram, began the firm now known as Alex. Reid & Lefevre.