The Doryphoros at the MIA / Minneapolis Institute of Art

(Quoted from the MIA entry for the Doryphoros):

The MIA’s Doryphoros, dating from the lst century B.C., is a Roman marble copy of a Greek bronze sculpture that was made between 450 B.C. and 440 B.C. by the sculptor, Polykleitos. It is the finest of the five known copies of the entire body of this famous masterpiece that have survived relatively intact. Representing an athlete (or possibly Achilles), this harmonious, balanced figure with idealized proportions, typifies art from the Classical p