Imperial diptych offerings to the emperor. However, the fact that the Barberini ivory was almost certainly not a diptych, but some kind of imperial icon without a second panel is a serious argument against the existence of the imperial diptych type. The two panels representing the empress Ariadne, in the Bargello in Florence and the Kunsthistorisches Museum in Vienna, also belong to the hypothesied imperial diptych type. They are the only central panels of such a diptych (other than the Barberini ivory) to survive, since all other fragments of such diptychs are from side panels. Imperial diptych In Late Antiquity, an imperial
Pisa Altarpiece panels of the altarpiece, which is the only documented work by Masaccio, are in various museums. Scholars hypothesize the reconstruction of the altarpiece based on a very complete description by Vasari. The painting contains six figures: the Madonna and Child and four angels. The Madonna is the centre figure and is larger than any of the others to signify her importance. Christ sits on her knees, eating grapes offered to him by his mother. Although he is an exceedingly babyish baby (in comparison to the babies of Masaccio's immediate predecessors, like Lorenzo Monaco or Gentile da Fabriano), the grapes are