As late as the mid-19th century, scholars had still not produced a single book specially devoted to the history of ancient painting. Therefore when drawing up a programme for the Gallery of the History of Ancient Painting, Klenze drew on the information about the history of painting contained in the works of Greek and Roman writers. A very important source in this area is the Natural History by the 1st-century A.D. Roman writer Pliny the Elder, the only encyclopaedia to have come down to us from the Ancient World. Pliny wrote about many artists, including Zeuxis, a celebrated master who lived in Greece at the end of the 5th and beginning of the 4th century B.C. In his painting Boy with Grapes Zeuxis depicted the grapes so realistically that birds flew down to peck them; then he put a boy next to the grapes and the birds flew down again. Zeuxis lost his temper, thinking that if he had depicted the boy as well as the grapes, the birds would have been frightened by him (Book XXXV, Section 36).
We know of Zeuxis's paintings of Helen, A Family of Centaurs and The Infant Hercules Strangling the Serpents from ancient written sources and very late reproductions in Roman murals (the House of the Vettii in Pompeii) and mosaics (Hadrian's Villa at Tivoli near Rome).