The Barberini ivory, a 6th century ivory diptych representing either Anastasius or Justinian I.

He acquired the Byzantine Barberini ivory ( it is not known how or from whom ) and offered it to Francesco Barberini: the work is now in the Louvre.

The Barberini ivory, a late Theodosian Byzantine Empire | Byzantine ivory carving | ivory leaf from an imperial diptych, from an imperial workshop in Constantinople in the first half of the sixth century ( Louvre Museum )

It is instructive to compare, for instance, the early Byzantine portrait of Justinian on the Barberini ivory with the portrait of Otto III in the Munich Gospels of Otto III ( Bayerische Nationalbibl.