Louis-Antoine Crozat, baron de Thiers, was one of three sons of Antoine Crozat, marquis du Châtel. Antoine and his brother Pierre ("le pauvre"), both from Toulouse, advanced to a position with the treasury of the states of Languedoc province. After amassing a considerable fortune, the brothers moved to Paris in 1703. Antoine continued to work, obtaining exclusive--and very profitable--rights of trade with the Louisiana territory. Pierre built a sumptuous residence, now destroyed, on the rue du Richelieu and dedicated himself to collecting the works of art with which he filled his home. Pierre Crozat collected both fine and decorative art objects in abundance--over 400 paintings, as many sculptures, some 18,000 drawings, as well as engravings, Chinese and Japanese porcelains, Italian ceramics, etc. He made purchases or sent agents to buy on his behalf in cities all over Western Europe, including Ghent, Amsterdam, London, Rome, Venice, and of course, Paris. The hôtel Crozat became a sort of artistic center, hosting many musical and artistic soirées, frequented by the artist Watteau among others. Pierre Crozat died in 1740; in his will he stipulated that a part of his belongings be sold after his death, with the proceeds going to the poor. A portion of the collection was thus acquired by the Duc d'Orléans. Crozat bequeathed the paintings and statues to his eldest nephew Louis-François, marquis du Châtel 1691-1750], the son of Antoine. Louis-François survived his uncle by only ten years. After his death in 1750, the sculptures were sold at auction in 1751 and the the Crozat paintings collection divided between Châtel's daughter, Louise-Honorine, later duchess of Choiseul, and his younger brothers, Joseph-Antoine, baron de Tugny, and Louis-Antoine. Tugny died the next year, and Thiers purchased his choice of the Crozat pictures from Tugny's heirs. After Thiers himself died in 1770, the Crozat collection was sold in 1772 through Denis Diderot [1713-1784] to Catherine II of Russia, and ultimately became part of the collection of the Imperial Hermitage Gallery in St. Petersburg. Likewise the Crozat pictures owned by the duchess of Choiseul were sold following her death, many of them to Catherine II as well. [Compiled from sources and references recorded on CMS]
Stuffmann, Margret. "Les Tableaux de la collection de Pierre Crozat." Gazette des Beaux-Arts 72 (1968): 5-142
Clément de Ris, Louis Torterat. Les amateurs d'autrefois. Paris, 1877. Reprint, Geneva, 1973: 183-207.