with peace and prosperity, and on the other hand the theme of Christian victory brought by Christ's patronage and blessing of the emperor. It introduces a new cosmic hierarchy into the representation of the triumph of the Roman Empire and is thus a highly political work designed to serve as imperial propaganda. The quality of the workmanship allows it to be attributed to an imperial workshop in Constantinople. Central panel The composition is arranged around a central plaque which dominates it by its motif as much as by its stylistic quality. The sculpted motif is a triumphant figure of an emperor on a rearing horse. In his right hand the emperor holds the butt of a lance, the other end pointed towards the ground, and in his left he holds his horse's reins. Behind the lance is the figure of a barbarian, identified as such by his hair, his bushy beard and above all by his clothes - his curved cap (similar to a Phrygian cap), indicating an eastern origin, a long-sleeved tunic and baggy trousers. Symbolising a Persian or a Scythian, he may represent the peoples defeated by the emperor – as a sign of submission he touches the lance with his right hand and raises his left hand - or be "cheering", perhaps a member of an auxiliary unit. Ernst Kitzinger noted as "remarkable... the amount of lively activity with which the central relief is packed", in contrast to the static figures at the centre of most diptychs. In his interpretation "The emperor has arrived on his charger this instant, his mantle still flying in the wind. It almost appears as though he had just passed through a low city gate which had caused him to tilt his head. He pulls in his reins and makes a rapid half-turn as he rams his spear into the ground to use it as a support in dismounting. ... In all Roman art there is no more spirited portrayal of an imperial adventus." In the lower right corner, under the horse, a woman lies on the ground. Her robe has slipped, revealing her right breast, and in her left hand she holds a fold of her robe containing fruits, symbols of prosperity. Her right hand is raised to the emperor's right foot in a gesture of submission. She personifies Earth, representing the emperor's universal domination and with the fruits symbolising the