Ernest-Ange Duez (1843-1896) was a French art friend of Sargent's. Duez, two years younger, was on the Salon jury of '81 that awarded Sargent the 2nd place medal for his painting Madame Ramon Subercaseaux (1880). They both had studios at the boulevard Berthier and were part of the same social circle that included Albert Besnard, Gabriel Fauré, and Joseph Roger-Jourdain.

Besides this painting, John would paint a portrait of Duez's wife in 1883. 

Duez was most famous for his landscapes and would never stop painting those, however, he would also have periods where he would concentrated on portraiture or on genre paintings.

Giovanni Boldini