Sommeil, or "The Sleepers"
by Gustave Courbet
Gustave Courbet was a French Painter of the "Realist" school, a reaction to 18th and early 19th Century Romanticism and a precursor to later Impressionism. This work was painted in 1866 (if I'm not mistaken, for an Ottoman sultan). It was one of several erotic works that got Courbet in a great deal of trouble. (To see an interesting alternate version of this image, go here.)