I was looking through several books on Italian drawings from the Renaissance and Baroque today when I chanced upon this. It’s a detail from a larger engraving of the Judgement of Paris, made around 1515 by an engraver called Raimondi, after a drawing by Raphael. The book said nothing about the fact that this drawing is clearly the source of Manet’s composition for Le dejeuner sur L’herbe. It amazes me that in regards to all of the ink spilled over Luncheon on the Grass, and in all that I’ve read about Manet, I’ve never seen a reference to the classical inspiration for the composition. (Apparently Raphael got his own inspiration for that grouping off a Roman sarcophagus.) Anyway, once I got home and googled the two titles together, I got about a million hits, and Manet is actually mentioned in the Wikipedia article on Raimondi, so no, I’m not the only one to notice this, or special or anything. 
It’s a fantastic composition, and I can see why it appealed to Manet; his Salon paintings often commented on art history (cf. Olympia). Manet had a conservative side, and perhaps references to art history helped legitimise the avant guarde nature of his artistic development to himself as much as to a prospective viewer.
