François Tronchin

François Tronchin (23 October 1704 – 7 February 1798) was a Swiss lawyer, banker, and collector. 
He knew many artists, Jean-Pierre Saint-Ours, Joseph Vernet, Jean-Baptiste Lemoyne, Étienne-Maurice Falconet, Nicolas Henri Joseph de Fassin, and philosophers, Voltaire, Denis Diderot, and Melchior Grimm.
He sold many paintings in his collection to Catherine II of Russia.