Late 2nd-early 3rd century AD. A Roman bronze sport helmet of 'Pfrondorf Type', with female features, possibly representing a gorgon (Medusa), comprising a two-part helmet with a back plate, the face piece originally with a removable inner mask; the skull embossed with stylised representations of hair along the sides and collected at the lower centre of the back to a chignon, the centre decorated by a blue enamel stone; on the upper part of the skull a two-headed snake, whose wide body is decorated with scales chiselled on the surface, long neck protruding on the two sides of the skull until the brow; the edge of the skull is decorated by punched triangles and a line representing the crown of the hair around the face; a small flat neck guard; a hinge is fastened through a pin the skull to the mask allowing it to be raised; the T-opening for the face was not always present in this type of helmet. See Robinson, R., The Armour of Imperial Rome, New York, 1975; Garbsch, J., Römische Paraderustüngen, München, 1979; Born, H., and Junkelmann M., Römische Kampf-und Turnierrüstungen, Band VI, Sammlung Axel Guttmann, Mainz,1997; D'Amato R. and Negin, A. Decorated Roman Armour, London, 2017; D'Amato R. and Negin, A. Roman Heavy Cavalry (1), Cataphractarii and Clibanarii, 1st century BC-5th century AD, Oxford, 2018.2.1 kg total including stand, 27cm (10 1/2"). From an important East Anglian collection of arms and armour; formerly in a Dutch private collection since the 1990s; previously in a Swiss family collection since before 1980; accompanied by a metallurgic analytical report, written by metallurgist Dr. Brian Gilmour of the Research Laboratory for Archaeology and the History of Art, University of Oxford, report number 144723/HM1364; and an academic report by military specialist Dr Raffaele D'Amato; this lot has been checked against the Interpol Database of stolen works of art and is accompanied by AIAD certificate number no. 144723-10011. This mask helmet belongs to the category of Roman mask helmets used during military games and pageants, which also functioned as training, such as those described by Arrian of Nicomedia in the ‘Tactica’.The simpler versions of such masks could also be used in battle, particularly by the heavy cavalry division (catafractarii"). The distinguishing feature of such masks is the removable central area, along with a two-part construction. The Pfrondorf helmet, now held in Stuttgart, which gives its name to the typology, is the best and most complete of such specimens, which are rare in such good condition. Helmets with a facial cut-out often display the image of Medusa, with reference to her terrifying ability to turn people to stone.