This irregularly broken fragment is the centre of a carved marble shield, originally of a wide oval shape and represented from the obverse centre as a series of concentric bands leading to the outer rim. In the centre appears a strikingly anguished, almost baroque mask of Medusa, and on the reverse are represented two stylised arm straps with broken, rough surface down the centre between them. The size of the fragment suggests an origin as a statuary attribute or, like the cuirass fragment on the South West pillar of the Dome (Soane M831/Vermeule 290), perhaps from a sculptured triumphal monument, although the Gorgeion is the attribute of divinities such as Minerva and those represented in her image.

A comparative Medusa head, of slightly less anguished expression, is presented in an enrichment of linked palmettes on the round shield carried by the figure of Roma (or, less likely,Virtus) in Frieze A of the Cancelleria reliefs¹.

Such shields also appear in the Neo-Attic reliefs showing an Athena of Pheidian type figure holding out her helmet or flying her owl, see the examples in the Ny Carlsberg Glyptotek, Copenhagen, and the Virginia Museum (of Fine Arts), Richmond, the former from Lansdowne House and the latter from the Lanckoronski collection in Vienna².

¹ see Filippo Magi, 'I rilievi flavi del palazzo della Cancelleria', Monumenti Vaticani di archaeologia e d'arte volume 6, Rome, 1945, III.
² See F. Poulsen, Catalogue of Ancient Sculpture in the Ny Carlsberg Glyptotek, Copenhagen, 1951, p. 171, no. 231a, plates volume III, Va; and Ancient Art in the Virginia Museum, Richmond, 1973, p. 122, no. 138.

First recorded in Soane's collection in J.M. Gandy, view of the Dome Area by night, 1811, SM 14/6/5.