Imperial diptych Imperial diptych In Late Antiquity, an imperial diptych is a theoretical type of ivory diptych, made up of two leaves of five panels each and each with a central panel representing the emperor or empress. They are so-named in contrast to consular diptychs. They were produced as unique examples, whereas each consular diptych was produced in large numbers to offer to the emperor on certain occasions, principally a nobleman's entry to the consulship. No complete example of an imperial diptych survives and so their existence is contested. The ivories specialist R. Delbrück has theorised that the 19 surviving fragments of
San Marco Altarpiece San Marco Altarpiece The San Marco Altarpiece (also known as "Madonna and Saints") is a painting by the Italian early Renaissance painter Fra Angelico, housed in the San Marco Museum of Florence, Italy. It was commissioned by Cosimo de' Medici the Elder, and was completed sometime between 1438 and 1443. In addition to the main panel depicting the enthroned Virgin and Child surrounded by Angels and Saints, there were 9 predella panels accompanying it, narrating the legend of the patron saints, Saints Cosmas and Damian. Only the main panel actually remains to be seen in the Convent of San Marco,