Nothing is recorded as to the life of Polycleitos; his age, as compared with that of Pheidias, is not accurately known. It is probable that he was rather younger than Pheidias, as he was working at a later date. Pliny gives the 90th Olympiad, or 420 B.C., as the date of Polycleitos. This may be the date of his great statue of Hera at Argos, the older temple of Hera having been burnt in 422 B.C., and it was probably near the end of the sculptor's life. No original works by the hand of Polycleitos survive, but several sculptures are known which can be shown with probability to have been copied more or less directly from originals, of which the character is thus ascertained. Polycleitos was famous in antiquity as the author of a methodical system of proportions for the human form. One in particular of his figures, the Doryphoros, was known as the _Canon_, and was adopted as the ideal type of a youthful male figure by later sculptors. This figure, and its companion the Diadumenos (see below, Nos. 500, 501), are known to us from copies. They are of vigorous make and square build, but somewhat heavy when compared with the graceful youths of the Parthenon frieze. But the words of Quintilian, who says (_Inst. Orat._, xii., 10, 7) that some critics objected to the works of Polycleitos as being wanting in weight and unduly elegant, suggest that the extant copies do not convey an accurate impression of the bronze originals, and in fact some of the numerous Doryphoros heads which have been found in Italy present a profile which strikingly recalls the profiles of the youths on the Parthenon frieze. Polycleitos was also noted for his technical skill and perfect workmanship. The works that have been associated with Polycleitos, in the British Museum, are here described (Nos. 500-503). A fragment, however, of a group of two boys playing with knuckle-bones (_Mus. Marbles_, ii., pl. 31), which was ascribed by Winckelmann to Polycleitos (_Hist. de l'Art_, Bk. vi., chap. 2; Pliny, _H. N._, xxxiv., 10), is no doubt of a later period, and is therefore omitted. [Sidenote: =500.=] Graeco-Roman copy of the Diadumenos of Polycleitos. Statue of a nude youth, tying a band (taenia) about his head. He stands principally on the right leg, resting lightly on the left leg, and has both hands raised. The left hand is lost. The band was made of bronze, and holes remain for its attachment. The left side of the face has been very much rubbed down. By the side of the figure is a tree-stump. That this figure is the Diadumenos of Polycleitos is indicated by its close resemblance in style to the figure at Naples, believed to be a copy of the Doryphoros (see No. 502). It would be a remarkable coincidence if we had two companion statues representing respectively a Diadumenos and a Doryphoros, known from the number of replicas to be copies of important works, and agreeing in style with what would be expected of the art of Polycleitos, but yet derived from independent sources.